Reviews and Records in Anatomy and Physiology. 105 
have observed that they multiply by a segmentation of their nu- 
cleus, and that the product of this division resembles precisely 
the parent. In some specimens observed by Lieberkihn, taken 
from a dog, he found the parent vesicle to contain sometimes 16 
segmented globules. But here the observations unfortunately 
ceased, and we are not aware that in any case or instance they 
have been extended beyond this point; that is, so as to show that 
the offspring of this segmentation which so closely resembles its 
parent pursues the same course and produces by segmentation a 
third series. The doctrine that individual animal forms may be 
unicellular or that an animal may be composed solely of a single 
cell, as advanced by Siebold and Kdlliker,* we regard as wholly 
untenable in the present state of science; for, aside from its being 
against the general analogy of individual zoological forms, it has 
not yet facts enough to sustain it merely as a point of observation. 
The cell is indeed typically the primordium of all organized 
forms, but true individual animal life seems to involve a cycle o 
relations not implied in single cells; in other words, these last 
must always lose their character as such in a definite form which 
belongs to the individual. Extended researches in Microscopy 
In all directions of the organic world,—all tend to establish the 
doctrine that sex lies behind all true individual forms,—that the 
ovum is the point of departure on one side, and the spermatic 
particle on the other,—and that by the conjunction of the two 
a new individuality is produced. There is indeed a most strik- 
ing and beautiful uniformity between the simple cell and the 
ovumina morphological point of view, or between the cell and the 
parent sperm-vesicle, thereby indicating a unity of idea and place 
in the first expression of life and the functional means of its cy- 
cle of actions; but without wishing to be mystical, it appears to 
us that life as expressed under the individual whether in its first 
or last forms,—as an egg ready to develope, or as a complete ani- 
mal, rises high above and implies. a great deal more than simple 
cell-conditions, Wear ue, then, that all true animals arise prima- 
tily or secondarily from ova, and therefore have sex, and that 
those animal-like forms so often se arasites or entozoa m 
ations. 
f the contents of the lower portion of the intestine of a fro 
be examined under the microscope, there will usually be dein 
mnumerable moving particles which give a very life-like aspect 
tothe whole field. "These belong to the infusorial genus Bodo of 
* Sicbold and Killiker, See their Zeitsch. fiir wissenschaftliche Zoologie, 1, p. 
270, and ibid p, 1, 
BCOND Serizs, Vol, XVIII, No. 52.—July, 1854. 4 
¢ 
