PROCESS OF FERTILIZATION IN THE CRAB 163 
greatly distends it (fig. 122) and the spermatophores are by some 
means transferred to this part of the receptacle where they lie 
in the mass of jelly. This prevents them from being lost at the 
time of molting when the chitinous lining is shed. Whether they 
are returned to this part of the receptacle after the molting has 
not been determined. The glandular part of the receptacle is 
rapidly reduced after the shell is shed, but I do not know what 
becomes of the secretion. During spawning the glandular por- 
tion is very much contracted (fig. 121) so that it is little more 
than a tube connecting the ovary with the chitinous receptacle. 
There is one possibility which may be mentioned here; the glandu- 
lar receptacle may secrete a semi-fluid substance and then, by 
contracting, force the spermatozoa into the lumen of the ovary 
just before spawning begins. As I shall show later, the sperma- 
tozoa are transferred to the ovary. This however is only a con- 
jecture as to the method of the transfer. The only time at which 
the receptacle is known to be actively secreting a substance is 
just before molting and it may simply be a device for retaining 
the spermatophores at the molting period. 
If a crab that has just begun to lay its eggs be opened, the 
lumen of the ovary and the oviduct will be found to be full of 
eges. Some eggs were taken from the lumen of the ovary with 
a sterilized pipette and placed in filtered sea-water. Since these 
developed into embryos it is evident that fertilization takes place 
in the ovary. Sections were made of eggs taken from the lumen 
of the ovary and from the oviduct and from these the phenomena 
of fertilization were observed, but we will return to this later. 
6. THE BEHAVIOR OF THE SPERMATOZOA 
-The spermatozoa of this crab are so very minute, the eggs SO 
relatively large and opaque, and the conditions for sperm entrance 
so difficult to reproduce on the microscopic slide, I did not see 
the living spermatozoon enter the egg. It is easy, however, to 
interpret the structures seen in sections of eggs taken at spawn- 
ing time, after one has observed the behavior of the spermatozoa 
under certain experimental conditions. We will proceed, there- 
fore, to a description of this behavior. 
JOURNAL OF MORPHOLOGY, VOL. 24, No. 2 
