966 The American Naturalist. [November, 
EMBRYOLOGY.’ 
Frog Embryos.—tThe surface views of early stages in the larval 
life of Rana temporaria presented by Friedrich Ziegler’ form a pleas- 
ing contrast to many of the crude representations too often seen, even 
in important papers upon amphibian embryology. As life-like and 
accurate reproductions of the actual conditions observed, his figures of 
the blastopore, medullary folds, mouth, olfactory pits and adhesive 
disks merit the highest praise, and the method he resorted to seems 
destined to lead to much more satisfactory observations and drawing 
than could be expected from the methods in vogue. He simply 
inclines the microscope tube into a horizontal position and observes 
the frog spawn in a test tube placed beneath the stage, the illuminator 
and diaphragm being removed. A large condensing lens is also used 
to concentrate gas-light or sun-light upon the embryos. It is to be 
hoped the author will publish a complete series of such illustrations 
of the ontogeny of some frog. 
Pineal Body in Amblystoma.—Immediately following the 
above article we find a short preliminary note by Albert ©. Eyele- 
shymer, of Ann Arbor, Mich. The presence in the embryo of two 
median dorsal outgrowths in the region of the pineal body is gener- 
ally conceded, but their relative importance and ultimate fate are 
matters of uncertainty. 
In amblystoma a crescentric evagination arises from the roof of the 
thalamencephalon when the larva is 5 mm. long; this is the epiphysis 
or posterior outgrowth. The presence of pigment in the inner ends of 
the cells and the behavior of their nuclei are strongly suggestive of 
phenomena seen in the optic vesicles. Much later, when the lens of 
the lateral eye is invaginating, a second median dorsal outgrowth arises 
from the posterior part of the roof of the prosencephalon. This is 
the paraphysis described by Selenka in reptiles. Subsequently both 
epiphysis and paraphysis undergo similar changes, but remain separate 
from one another. 
The author considers the paraphysis of less importance than the 
epiphysis, but does not commit himself as to its probable nature. 7 
The epiphysis may have been of special use as a sense organ when the 
This department is edited by Dr. E. A. Andrews, Johns Hopkins University. 
Anatom. Anzeiger, vii. April, 1892. 
