358 Wisconsin Academy of Sciences, Arts, and Letters. 
karyokinetic figures as occurring in the vegetative hyphae but does 
not figure nor describe the process of nuclear division. He finds 
that the nuclei, evident up to this time, begin to disintegrate as 
the zygospore matures and its protoplasm becomes spongy and 
filled with oil. This disintegration is a process in which the 
nucleole becomes smaller and finally disappears. The nucleus 
then becomes vacuole-like. A few nuclei, which are two or three 
times larger than those entering the zygospore at the time the 
gametes fuse, remain in the zygospores longer than do the other 
nuclei, but ultimately disappear. In another paper, without figures, 
Leger (1895b) has reported on the conditions he has found in 
species of Pilobolus, Rhizopus, Chaetocladium and Mortierella, 
together with those forms previously studied with Dangeard. He 
describes the structure of the nucleus in the vegetative hyphae 
in all the forms as similar to that described by Dangeard and 
himself. He indicates a point of interest as to the fate of the 
nucleus in the mycelium and the columella in that the nuclei 
become reduced to nucleoles which persist after all other traces of 
the protoplasm have disappeared. 
Istvanffi (1895) describes the nucleus in Mucor sp. He finds 
that the nuclei are scattered thruout the entire protoplasm; that 
they are elliptical or spherical in shape and usually provided with 
a nucleole. In spore formation only one nucleus enters each spore. 
During preparation for germination, the spore is observed to 
have eight to ten nuclei. In the tips of hyphae where he considers 
that the nuclei are youngest, he states that they may consist of only 
a small homogeneously-stained body, not exceeding Ifi in diameter. 
Harper (1899) in his description of spore formation of Pilo¬ 
bolus states that the vegetative nuclei of this form divide in the 
basal bulb, thus giving rise to the nuclei that enter the sporange 
during its development. He also finds that the nuclei divide in 
the protospore and in the swelling spore in preparation for germi¬ 
nation. In none of these references to nuclear division does he 
describe the structure of the nucleus or indicate how it divides. 
However, he figures several nuclei, each consisting of a dense 
central body enclosed by a granular nucleoplasm and a nuclear 
membrane. He also illustrates several division figures, each con¬ 
sisting of an elongated body, at the two poles of which are several 
dense granules; the two groups of granules are connected by one 
or more fibrous strands. 
