No. 3.] ALLOLOBOPHORA FOETIDA. 495 
a thin layer of the albumen of the cocoon. In this case, it is 
well to preserve and mount the eggs in the cocoon, in order to 
test the stage of development reached by the spermatozoa, by 
ascertaining whether the eggs are at the exact stage to be fer- 
tilized ; for, as stated above, I have found freshly deposited 
cocoons containing eggs past the fertilization stage. Com- 
parative measurements of the spermatozoa in the slime-tube, in 
the freshly deposited cocoon, and in the cocoon containing fer- 
tilized eggs, show only a slight difference in size. I wish 
here to correct a statement made in my preliminary note (5). 
I stated there that the full-grown spermatozoa taken from 
the freshly deposited cocoon were about 2% times the length 
of those in the immature cocoon, and that they did not respond 
to differential staining. Further investigation has proved that 
the structures from which these measurements were taken are 
not normal spermatozoa, and as at the time I had not learned 
to control the investigation by preserving some of the eggs, 
I am convinced that these measurements were taken from 
spermatozoa in cocoons containing fertilized eggs. These 
spermatozoa of abnormal growth vary greatly in size, and are 
relatively far more numerous in the cocoons containing ferti- 
lized eggs. In some cases they appear to be developed by an 
abnormal growth of the head alone, while in others, though 
all parts select the same stain, the spine, head, and tail can be 
clearly identified. When stained with a chromatin and plasma 
stain, they, as a rule, select the latter; for example, with 
Biondi-Ehrlich all parts select the red, whereas the heads of 
the normal spermatozoa select the green. The large speci- 
mens suggest the giant spermatozoa of authors, though in this 
case they appear to be merely hypertrophied spermatozoa 
(text Fig. 1).1 In the cocoons there are relatively few sperma- 
tozoa in which the spine, head, middle-piece, and tail respond to 
differential staining as do those in the slime-tube. Their 
1 In cocoons containing fertilized eggs, besides the individual spermatozoa, 
there appear to be attenuated masses of degenerating spermatozoa. Just such 
masses can be seen in certain spermathecae in which the spermatozoa show 
abnormal features, and in some cases from two to four heads are fused, making a 
relatively thick mass, whereas the tails are separated and can be counted, indicat- 
ing just how many heads are fused. 
