720 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
genital pores are ever united in tlie act of copulation. On the other 
hand, the planting of spermatophores on the surface of the body at any 
point that happens to come first is a common occurrence. Prof. 
Whitman has followed the track of the spermatozoa from the point of 
penetration to the ccelomic cavity in which the ovaries lie, but he has 
not yet determined when or how the spermatozoa pass through the wall 
of the ovisac ; that they do so seems to be an inference justified by all the 
known facts. As the ovarian walls are represented by a thin membrane 
which becomes enormously distended as the eggs enlarge to maturity, the 
difficulty of penetration cannot be great ; Peripatus and the Turbellaria 
seem to show that spermatozoa are capable of effecting the passage 
automatically. The discovery of spermatozoa projecting through the 
ovarian walls of Peripatus, as described by Moseley and Sedgwick, ceases 
to be a mystery. 
The author gives a catena of authorities which appears to him 
to indicate that the original function of the spermatophore was what it 
now is in the Turbellarians, Rotifers, Dinophilus. and Clepsine — the injec- 
tion of spermatozoa through the body-wall. This mode of impregnation 
is an important advance on the more primitive mode of setting the 
seminal elements free in the water. This deposition of sperm-capsules 
at random is further improved upon by restricting the act to a definite 
region, as the clitellum of Annelids, or the region around the external 
openings of the oviduct in crayfishes. 
Prof. Whitman very justly remarks that what he formerly regarded 
as positive proof, either of self-fertilization or of parthenogenesis, is now 
open to some doubt. 
An account is given of what was seen in the case of a new species of 
Clepsine (C. plana) ; when first placed in a dish several long white bodies 
were observed to be attached by one end to the dorsal surface of one 
or two individuals ; those were naturally thought to be parasites. But, 
when put under the Microscope, a stream of spermatozoa was seen slowly 
issuing from the end that had been detached. Closer observation showed 
the mode of deposition ; one individual, coming in contact with another, 
fixed itself by its oral sucker to some convenient point, and then, while 
pressing its protruded male pore against the back of its fellow, planted 
a fresh sperm-case. During the operation, which lasted only a few seconds, 
the region of the genital pores was more or less constricted, somewhat 
as it is in the act of forming an egg-cocoon. The case was, very likely, 
filled with spermatozoa by this act. This operation was repeated by the 
same individual several times in a period of thirty minutes ; one of the 
first deposited spermatophores was 8 mm. long and 1 mm. wide ; some 
of the last only 3 mm. or even less. 
In the spermatophore it is possible to distinguish (1) a short con- 
stricted basal portion with a single tubular lumen, formed in the median 
unpaired portion of the male organs ; (2) an elongated body with a 
double saccular lumen^ formed in the enlarged terminal portions of 
the common vasa deferentia ; and (3) a free end, consisting of two parts 
with the lumen closed or reduced to a narrow line, and formed in the 
ends of the ejaculatory ducts. The wall of the spermatophore is com- 
posed of two well-defined layers, the outer of which is thin, transparent, 
and cuticula-likc, while the inner is denser, thicker, and stainablc. 
