of germinal matter have increased at one point, and have extended from the spore. They continue to grow rapidly, being protected only by a very thin layer of formed material. e.-A spore which has much increased in size, but from which no offshoot has proceeded. Several thick layers of formed material are seen. The oldest layer is outside, the youngest in immediate contact with the germinal matter. f.-A spore from which an off-shoot has proceeded. The germinal matter of the off-shoot has been destroyed, while that of the spore retains its vitality. g.-A part of the thallus, the germinal matter of which is dead. The external tubular membrane retains its physical characters. h.-Portions of thallus, in which the germinal matter is increasing most rapidly in certain spots. Here branches are formed. i.-A young branch growing. k.—An older part of the thallus, showing the septa of formed material and the points at which the germinal matter was originally continuous. The formed material is thicker than in h or i, and the germinal matter is a little shrunk within its tube. 7.-A spore from which an off-shoot has proceeded. The formed material is seen to be very thin at the summit, where growth is occurring most rapidly. m.-Spore with two off-shoots from opposite surfaces. These have grown and are giving off branches, but the continuity between the germinal matter in these, and that in the spore still exists. n.-The germinal matter of the spore is dead, and forms a mass which has collapsed within the envelope, while the germinal matter in the off-shoot retains its vitality and is growing rapidly. o.-A very old spore which has germinated and given off an off-shoot. From having been exposed to conditions unfavourable to its free extension, the formed material has increased enormously in thickness by the deposition of successive layers upon its internal surface. p.-A part of one of the stems which grow into the air, bearing on its summit oval capsules, from the germinal matter of which the spores are formed. r.—A separate capsule. th deposition of successive layers urea is 1 rt of one of the stems which grow Teorem, its sum nit val capedes, iron tr wh the spores are formed. P.--A r |