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POPULAR SCIENCE REVIEW. 
or to the common supporting stem, that the luxuriant colony- 
forms of this beautiful genus are produced. A single monad 
of Codosiga jpulcherrima is shown at Plate III. fig. 10 in the act 
of dividing into two by this last-named characteristic mode of 
fission, and in which process it will be seen that the division ex- 
tends to both the hyaline collar and the flagellum. These several 
processes of multiplication — by fission in a twofold manner and 
by the breaking up of the parent body, after encystment, into 
locomotive spores — are found to persist not only throughout this 
special collar-bearing group, but must now evidently be accepted 
as presenting the normal method of reproduction among all 
Protozoic structures. Preceding this more important mode of 
increase by the resolution of the parent body into spores, it 
frequently happens that two or more individuals coalesce or 
fuse intimately, mostly in an amoeboid form, with one another, 
and produce one single capsular encystment. This process, how- 
ever, does not appear in all cases to be essential. Taken as a 
whole, the representatives of the protozoic or unicellular animal 
sub-kingdom are thus shown to agree in their reproductive and 
developmental phenomena with the unicellular and other lower 
cryptogamic plants, and might therefore with equal justice be 
appropriately denominated cryptogamic animals. These two 
animal and vegetable groups again exhibit a further striking pa- 
rallelism, inasmuch as neither in the former does a true egg, nor 
in the latter a true seed, constitute the essential reproductive 
product, as is the case with all of the more highly organized 
structures on either side. Among the developmental phenomena, 
supplementary to the foregoing, presented by the collar-bearing 
group here specially considered, that associated with the build- 
ing up of the protective sheath of the loricated genus Salpingceca 
is well worthy of notice. This structure, as shown in the case 
of S. ampulla at Plate IV. figs. 13 and 14, takes its origin as 
a mere mucus-like excretion from the surface of the monad’s 
body, and at a period prior even to the appearance of the collar. 
In a very short time after its excretion, the lorica acquires its 
normal consistency, and is then of considerable solidity, as is 
proved by its retention of its form for a considerable interval 
after the death of its original occupant. 
Absorbing as the investigation of these minute independent 
collar-bearing monads is sure to become to any microscopist 
adopting the same as a subject for study, on the merit of their 
intrinsic beauty and variety of form alone, it has yet to be 
shown that they possess a still more interesting and important 
bearing with reference to their relationship or affinity with 
certain other animal organisms. Prof. H. James Clark, the 
authority already quoted as the first to report the occurrence 
within American waters of some three or four varieties of these 
