to any principle of utility. Adaptation is evident enough, but each species is as well fitted for its life as any other, and no transposition or change of the distinctive specific characters or any set of them would in any conceivable degree reduce this adaptation. No one can say that any one of the actual distinctive characters or any combination of them enables their possessors to survive in larger numbers than would otherwise be the case. One or two of these traits, as objects of sexual selection or as recognition marks, have a hypothetical value, but their utility in these regards is slight or uncertain. It is customary at present to look with disfavor on sexual selection as a factor in the evolution of ornamental structures, and the psychological reality of recognition marks is yet unproved, though not at all improbable.

It may be noted, in passing, that the prevalent dull yellowish and olivaceous hues of the female orioles of all species is clearly of the nature of protective coloration.

Professor Vernon L. Kellogg has shown statistically that certain specific characters among insects have no relation to the process of selection. Among honey bees the variation in venation of the wings and in the number and character of the wing hooks is just as great when the bees first come from their cells as in a series of individuals long exposed to the struggle for existence.

Among ladybird beetles of one species (Hippodamia convergens) 84 different easily describable 'aberrations' or variations in the number and arrangement of the black spots on the wing covers have been traced. These variations are again just as numerous in individuals exposed to the struggle for life as in those just escaped from the pupal state. In these characters there is, therefore, no rigorous

Such spe

choice due to natural selection. cific characters, without individual utility, may be classed as indifferent, so far as natural selection is concerned, and the great mass of specific characters actually used in systematic classification are thus indifferent.

And what is true in the case of the orioles is true as a broad proposition of the related species which constitutes any one of the genera of animals or plants. All that survive are well fitted to live, each individual, and therefore each species fitted to its surroundings as the dough is to the pan, or the river to its bed, but all adaptation lying apparently within a range of the greatest variety in non-essentials. Adaptation is the work of natural selection: the division of forms into species is the result of existence under new and diverse conditions.

To the general rule that closely allied species do not live together there exist partial exceptions. It may be well to glance at some of these, for no rule is established until its exceptions are brought into harmony with the phenomena which illustrate the rule.

The most striking case of this sort known to us is that of the Pescado Blanco of the volcanic lakes of Mexico, these constituting the genus Chirostoma in the family of Atherinidæ.

In the large lake of Chapala in central Mexico, tributary to the Rio Lerma, one species, Chirostoma estor, has been known for years. It is a pale, translucent fish of elongate form, about fifteen inches in length, with very delicate flesh, and it is much appreciated as a food fish under the local name of 'Pescado Blanco de Chapala." In a recent visit to that region, the Pescado Blanco was found to be abundant in the lake, but to the great surprise of the writer, in the same catch of the net were found

under the same general guise of size and appearance some half a dozen distinct but closely related species of Pescado Blanco. In each case the different species most nearly related seemed to be found together, an exception to the rule otherwise almost universal among animals and plants. Later explorations of Dr. Seth E. Meek in this and other lakes confirmed and magnified this anomaly. The genus Chirostoma is confined to the lakes of the tablelands of Mexico. It includes three groups or subgenera: Chirostoma proper, green in color and with firm, smooth scales; Lethostole, with smaller scales, rough edged, the body white or translucent, and Eslopsarum, of smaller species, also white, but with still larger scales, larger than in Chirostoma or Lethostole. The species were found to be grouped as follows:

groups Eslopsarum and Lethostole have diverged from it, and that the numerous species of the last-named type in the large lakes, Chapala and Patzcuaro, have been formed by mutations in the sense of the use of the word by de Vries. But it is possible that these species have been formed by isolation, and that species thus formed have invaded the territory of other species. The shifting of the shores of these volcanic lakes and of the hydrographic basins to which they belong is among the possible causes to be considered.

Another curious case of the occurrence in one locality of similar species is found in the genus Eviota of the family of Gobiidae or gobies.

Eviota contains very minute fishes of the coral reefs, translucent green in color, plain or blotched with orange and marked with black spots. One species one and a half inches long (Eviota abar) is found in Japan, and one an inch long (Eviota personata) in the West Indies. The other species are all less than an inch in length, some of them but half an inch, perhaps the smallest of all vertebrate animals. One of these, Eviota epiphanes, is found in crevices in the coral reefs of Hawaii. Another, Eviota miniata, is recorded from Guam. All the remaining species, including those most closely related, are known only from the crevices of coral heads in Samoa. Most of the known specimens, hundreds in all, were obtained by the writer and his associates in Apia and Pago Pago. Our native assistants would dive for these coral masses, and on cracking them, the little fishes would be found in their channels and interstices. In Samoa the following species occur: Eviota zonura, E. smaragdus, E. prasites, E. afelei, E. sebreei, E. pruinosa, E. herrei, E. distigma. It would seem as if these species could not have had a geographic origin in the ordinary sense, for they are all grouped

together in the same neighborhood. It is, however, possible that the isolation of a part of the reef or even of that of a single coral head might in long periods serve the same purpose.

Enneapterygius is a genus of blennies in size and distribution closely parallel with Eviota. It contains species of moderate size found in the Gulf of California, in New Zealand, the Red Sea and Japan. In these same coral heads, species of this genus also occur, all of them extremely minute, much smaller than their relatives in other waters, and scarcely larger than the species of Eviota, among which they live. These minute fishes are mostly red in color, sometimes partly black. Again one species (Enneapterygius atriceps) is found in the Hawaiian reefs, and again six species (E. minutus, E. hemimelas, E. hudsoni, E. tusitala, E. cerasinus and E. tutuila) live together in the coral heads of Samoa.

The more usual distribution of a group of closely related fishes may be shown by the group of silver-fin minnows, the section Erogala, in the genus Notropis among the fishes.

All these are small minnows, with large scales, and with the dorsal fin marked by a large black blotch on its last rays above. This fin in the males is tipped with a broad stripe of silvery or milk-white pigment, and sometimes also shaded with bright red, orange or blue, very conspicuous in the breeding season.

The simplest, most primitive and most widely distributed form is Notropis whipplii of the Mississippi Valley. Near to this in the Upper Tennessee is Notropis galacturus. In the Ozark range is Notropis camurus. Farther south a black spot appears at the base of the tail. This marks Notropis notatus in the Rio Colorado of Texas, Notropis venustus in the Rio

Sabinal, Notropis cercostigma in Pearl River, and Notropis stigmaturus in the Alabama. On the eastern part of its range, the nearest relative of Notropis whippli is Notropis analostanus of the Potomac. Near to this is Notropis niveus of the North Carolina rivers and Notropis chloristius of the Santee. Other variants from these are Notropis eurystomus of the Chattahoochee, Notropis xanurus of the Allamaha, Notropis cæruleus, callistius and trichroistius of the Alabama and Black Warrior, the last two with scarlet on the dorsal. Finally come the most specialized the most specialized extremes, Notropis pyrrhomelas of the Santee and Notropis hypselopterus of the Mobile. Each southern river has one or more species of this type, and the streams of Georgia have been invaded from the north and from the west, the two types meeting in the basin of the Alabama.

In the little group of minnows called Hydrophlox, another section of the genus, Notropis rubricroceus, and its allied species, scarlet, black and golden, are distributed in precisely the same fashion, and about the same number of species are developed. Those found in the Mississippi River have the widest range of distribution and the least specialization in their traits. Those in the clear waters of the southern slope of the Blue Ridge are most intensely colored, most specialized in the traits, and show the narrowest range in distribution.

If fishes were as easily preserved, measured and examined as birds, and if they were studied by as many keen eyes, we might find perhaps that each of these species is again broken up into races or subspecies, their traits determined in some degree by their individual parentage, in larger part by the local selection they have undergone in their diverse waters and surroundings. This is certainly probable in

the case of fresh-water fishes, but with marine fishes there is greater freedom of migration, the species are perhaps largely of more ancient origin and intergrading forms are much more rarely recognized.

The degree of fulness and accuracy in the recognition of subspecies marks the degree of progress in any branch of systematic or of faunal zoology and botany. It is the tyro who, as Linnæus suggests, sees the problems of geographical distribution in the large. It is the master who follows step by step the footprints of the Creator in the molding and distribution of life. DAVID STARR JORDAN.

STANFORD UNIVERSITY.

SCIENTIFIC BOOKS.

The Waterlilies: A Monograph of the Genus Nymphaea. By HENRY S. CONARD, Senior Harrison Fellow in Botany, University of Pennsylvania. Published by the Carnegie Institution of Washington. 1905. Pp. xiii + 279. 4to, 30 plates and 82 figures in the text.

This thick volume, which is listed as 'Publication No. 4' of the Carnegie Institution of Washington, appeared several months ago, and attracted immediate attention on account of its excellence of paper, type, presswork and plates. In the style of its publications the institution is setting a high standard which can not but favorably affect scientific publication throughout the country. The plates are from drawings (some colored) and photographs, which have been very faithfully reproduced. The text-figures, while largely outlines, are also well done, adding greatly to the value of the work.

Turning now to the text, we find a chapter given to a historical sketch, followed by another devoted to structure, still another to development, one to physiology. The central chapter devoted to taxonomy is the longest and most important, and this is followed by brief discussions of distribution, hybrids and 2" Tyro fit classes: magister fit species."

garden varieties, culture and uses and an, extended bibliography. From the preface we learn that nothing like a complete synopsis of the waterlilies has hitherto been put before the English-speaking world,' and indeed it appears that it is more than eighty years since the last complete treatment in any language, i. e., De Candolle's in the 'Prodromus' (1824). The present work is the result of studies undertaken by the author in the botanical garden and laboratories of the University of Pennsylvania, supplemented by living and preserved specimens and material from many sources, including that in the herbaria in Kew, British Museum, Linnean Society, Berlin, Munich, etc.

It would be pleasant to summarize, or quote from the historical chapter in which many interesting facts are brought together in very readable form. Likewise there is much of interest and importance in the chapter on structure, which includes gross and minute anatomy, and in the next chapter on the physiology of the plants (including a discussion of the cause of the opening and closing of the flowers), but there is no space here for this. The reader is recommended to peruse the interesting chapters for himself.

The

The chapter on taxonomy is the one of most general interest to the ordinary reader. author prefers the name Nymphaea to Castalia for the genus, reserving the latter for one of the subgenera. The species are arranged under two principal groups, viz., (I.) Nymphaeae Aprocarpiae (with carpels free from one another at the sides) and (II.) Nymphaeae Syncarpiae (with carpels completely fused with one another at the sides). Two subgenera are recognized in the first group, Anecphya, with but one species, N. gigantea (Australian), and Brachyceras, with twelve species, N. elegans (Texas and Mexico), N. ampla (tropical and subtropical America) N. flavo-virens (probably Mexican), N. stellata (southeast Asia), N. coerulea (Africa), N. micrantha (West Africa), N. heudelotii (Africa), N. ovalifolia (East Africa), N. calliantha (Africa), N. capensis (South Africa), N. sulfurea (Africa), and N. stahlmannii (Africa). In the second group the subgenus Castalia in

cludes seven species, N. mexicana (Florida, Texas, Mexico), N. tetragona (eastern Europe, Asia, North America to Australia), N. fennica (Finland), N. candida (northern Europe and Asia), N. alba (Europe and North Africa), N. odorata (eastern United States), and N. tuberosa (central United States); the subgenus Lotos, four species, N. lotus (Egypt), N. zenkeri (Africa), N. pubescens (East Indies), and N. rubra (East Indies); the subgenus Hydrocallis, ten species, N. amazonum (tropical America), N. rudgeana (tropical America), N. blanda (Guatemala), N. lasiophylla (Brazil), N. gardneriana (Brazil), N. jamesoniana (western South America and Porto Rico), N. stenaspidota (Brazil), N. tenerinerva (Brazil), N. oxypetala (Equador) and N. gibertii (Paraguay). It is noteworthy in this day when almost every monographer finds a lot of new species in his material, as a matter of course, that Doctor Conard describes but one new species, viz., N. ovalifolia, and a few new varieties. A second new species, N. zenkeri, by Professor Gilg, of Berlin, is here printed for the first time, although the name has been used for some time in European herbaria.

The closing chapter, mostly devoted to cultural directions, can scarcely be read without making one want to undertake the growth of some of these interesting plants. . Beginning with such suggestions as 'the care of them is very simple; the pond or tank may be only a large bucket or a half barrel,' Doctor Conard proceeds to more and more elaborate suggestions, some of which can not fail to tempt his readers to make a beginning in their cultivation.

The author is to be congratulated upon having made such a notable contribution to botanical science. CHARLES E. BESSEY.

THE UNIVERSITY OF NEBRASKA.

American Insects. By VERNON L. KELLOGG, Professor of Entomology and Lecturer on Bionomics in the Leland Stanford Jr. University. New York, Henry Holt & Co. 1905. Pp. 674.

In recent years a good many text-books or general works on the insects of America have

6

been published. Several of these have been limited to special fields, such as The Butterfly Book' and 'The Moth Book,' by Dr. Holland, and The Insect Book,' by Dr. Howard, the latter a companion book to Dr. Holland's volumes, covering the other orders of insects excepting the Coleoptera. Several text-books have, however, included the whole subject, among which may be mentioned Comstock's 'Manual for the Study of Insects,' Packard's 'Text-book of Entomology,' and volumes relating to insects more particularly in economic relations, such as Smith's 'Economic Entomology,' and Sanderson's 'Insects Affecting Staple Crops.' The best foreign work in English covering the general subject is Dr. Sharp's two volumes on insects in the Cambridge Natural History series, which remains the best work of its kind so far produced. Dr. Sharp's work, however, applies to the insects of the world. The volume prepared by Professor Kellogg, as indicated in the title, is limited practically to American insects, and is somewhat broader in scope than any of the American text-books so far published. The insect field in all its relations is so vast that it becomes a very difficult problem to include it even in a general way in a single volume, but Professor Kellogg has accomplished this very satisfactorily, on the whole.

As indicated in his preface:

This book is written in the endeavor to foster an interest in insect biology on the part of students of natural history, of nature observers and of general readers; it provides in a single volume a general systematic account of all the principal groups of insects as they occur in America, together with special accounts of the structure, physiology, development and metamorphoses, and of certain particularly interesting and important ecological relations of insects with the world around them. Systematic entomology, economic entomology, and what many be called the bionomics of insects are the special subjects of the matter and illustration of the book.

The structure and physiology of insects is gone into in considerable detail in the opening chapter. Metamorphosis and systematic classification of insects are rather briefly considered. The different orders and families of insects are then taken up seriatim, from the