MNor2.) WPIVNING ACTIVITIES OF PROTOPLASM. 371 
was not followed directly, but was seen later to have had a 
markedly degenerating course. 
Wherever such abnormal processes of membrane formation 
by spinning were watched, the processes differed from the 
normal filaments in being more irregular and unrestrained in 
protoplastic character ; there was less of direct thread forma- 
tion, more of tufts or brush-like processes, which were unstable 
in progress and even returned altogether to the egg covering. 
In the normal eggs the spinnings were swift, straight, smooth, 
direct, and continuous in their progress, neither ramifying nor 
returning. They seemed more homogeneous optically, and had 
not granules scattered along their course, as the abnormal 
spinnings often had for a considerable distance. Normally 
the threads came to be of about even length at about the same 
moment, while in abnormal eggs they were at a given moment 
unlike at almost all points of the periphery, the most perfect 
being formed always about the region of entrance of the first 
sperm. 
In normal eggs, the threads, having reached a certain, but 
rather variable, distance from the egg, appeared to fuse at their 
tips and then to spread out their substance there, so as to form 
a ceiling film. Increase of outflowing substance soon thick- 
ened the pellicle thus made, and almost simultaneously the 
threads themselves proceeded to fuse along their length, either 
by access of material from the egg over them, their linear 
extension having been to a great degree stopped, or by a 
spreading out of their substance as they continued to be formed 
from the rear; or perhaps even by exudations or secretions 
from them. 
The distance from the egg at which the threads began to 
fuse at their tips was variable ; when it took place at but a 
short distance, the film so formed was raised and extended by 
continued elongation of the threads, the lengthwise filling in 
beginning then or later, as the case might be. 
And in this manner was a striated membrane seen to be 
formed about sea-urchin eggs. 
Starfish eggs. —It has been commonly observed that, just at 
the region where the so-called polar globules are expelled, the 
