A History of Infusoria: Including the Desmidiaceae and Diatomaceae, British and Foreign

Front Cover
Whittaker and Company, 1861 - Desmidiaceae - 968 pages
 

What people are saying - Write a review

We haven't found any reviews in the usual places.

Other editions - View all

Common terms and phrases

Popular passages

Page 299 - This remarkable body when completely evolved (fig. 18/.) consists of two portions — a rigid spiculum-like portion acutely pointed at one end, and continuous at the opposite end with the second portion, which is in the form of an excessively fine filiform appendage less than half the length of the spiculum : this second portion is generally seen to be bent at an angle on the first, and is frequently more or less curved at the free end. The form of the evolved trichocysts is best observed in such...
Page 227 - The latter has some, although a very limited, power of locomotion ; which is effected by exserting its pseudopodia to their full length, attaching itself by them to a piece of seaweed, and then contracting them like india-rubber, so as to draw the shell along with them. Some of the acephalous mollusks do the same by means of their byssus. This mode of progression is, however, exceedingly slow ; and I have never seen, in the course of twenty-four hours, a longer journey than a quarter of an inch accomplished...
Page 218 - ... segments, and narrowed between these into connecting stolons, the shell being probably produced by the calcification of their outer portions. And this view he supports by the results of the examination of a number of specimens, in which reparation of injuries has taken place. Regarding the Reproduction of Orbitolites, he is only able to suggest that certain minute spherical masses of sarcode, with which some of the cells are filled, may be...
Page 231 - Foraminiferae. 10. In the vast amount of pelagic Foraminiferae, and in the entire absence of sand, these soundings strikingly resemble the chalk of England, as well as the calcareous marls of the Upper Missouri, and this would seem to indicate that these also were deep-sea deposits.
Page 218 - Lagence ; but they appeared to constitute the entire mass, and not merely a part of the animal. I am inclined to think they are only desiccated portions of the animal, separated from each other in consequence of the absence of any muscular or nervous structure. It may also be questionable if the term "ova" is rightly applicable to an animal which has no distinct organs of any kind.
Page 108 - ... might be due to a slight portion of a siliceous cement which the cautious use of an alkaline solution might remove without destroying any but the most minute shells of the Diatoms. As the case appeared a desperate one, a " heroic remedy " was applied, which was to boil small lumps of the diatomaceous mass in a strong solution of caustic potassa or soda. This proved to be perfectly efficacious, as the masses under this treatment rapidly split up along the planes of lamination, and then crumbled...
Page 4 - ... cells. In general, its quantity is merely sufficient to hold the fronds together in a kind of filmy cloud, which is dispersed by the slightest touch. When they are left exposed by the evaporation of the water, this mucus becomes denser, and is apparently secreted in larger quantities to protect them from the effects of drought.
Page 389 - ... kind of snap and moved slightly forwards." Mr. Dyster is inclined to think that the Oscillatoria passed through the anterior ring-like portion of the apparatus. I have not seen the animal feed, but on structural grounds I should rather have been inclined to place the oral aperture at (a, fig. 13,) and to suppose that the food would pass above the anterior ring. The apparatus is destroyed by caustic potash, but remains unaltered on the addition of acetic acid; it is therefore, probably, entirely...
Page 52 - If one half of a spindle-shaped or ellipsoidal cell chiefly or exclusively admits material, the other half, on the contrary, giving it out, the cell moves towards the side where the admission takes place. But as in these cells both halves are physiologically and morphologically exactly alike, so it is that it is first the one and then, the other half which admits or emits, and, consequently, the cell moves sometimes in one, sometimes in the opposite direction.
Page 240 - ... Carpenter, I cannot help deploring the excessive multiplication of species in the present day, and I would include in this regret the unnecessary formation of genera. Another Linnaeus is sadly wanted to correct this pernicious habit, both at home and abroad. The group now under consideration exhibits a great tendency to variation of form, some of the combinations (especially in the case of Marginulina) being as complicated and various as a Chinese puzzle. It is, I believe, undeniable, that the...

Bibliographic information