82 ME. LEBBOCK’S ACCOUIsT OF THE TWO ]METHODS OF EEPEODECTIOX 
moment engaged in a true act of coition. Moreover, the form of the papilla, which can 
scarcely be called a penis, justifies the inference that the act of intromission, if any, 
would be short and easily interrupted. At any rate, I must leave the question as to the 
mode of introduction of the spermatozoa, undecided for the present. The facts to be 
hereafter mentioned as to the development of the ephippial egg render it probable that 
the impregnation takes place at an early period in the development of the ovarian egg, 
which, unless the act is effected, gradually disappears. 
Bajphnim may, however, be found in every stage of ovarian development united to one or 
two males. I have found them so when the ovaries have been occupied only by nucleated 
ovarian masses, when the eggs have been almost ready to escape into the receptacle, and 
when the ephippium has been almost mature. In these cases the coition is probably 
rvithout any effect; and, indeed, though I have very seldom seen specimeirs with 
ephippia where I could find no males, and though the abrmdance of the males appear’s 
to vary with the number of the ephippia, yet I have often confined males and females 
together in the hope of being thus enabled to trace out the manner of the impregnation 
of the ephippial egg, but without succeeding in any one instance. 
Thus, on the 30th of September, two specimens which were confined together were 
in coition : this lasted for three-quarters of an hour after I first observed them. The 
female had then, at the centre of the right ovary, an agamic egg commencing, formed 
of a somewhat enlarged germinal vesicle, surrounded by some oil-globules and brown 
granules. On the evening of October 2nd, I again found these two specimens in coition, 
for at least three-quarters of an hour. At seven o’clock on the morning of the 3rd, I 
found that eggs had been deposited in the receptacle during the night, and the pah were 
again in coition. In the ovary were only the usual ovarian masses. On the 4th, 5th and 
6th they were again in coition, and on the morning of the 7th a fresh set of eggs had 
been deposited in the receptacle. Again, on the 1 9th of September, I placed eleven 
females in a glass with about as many males, and watched them till the 1 9 th of October, 
when two females and three males were still alive, and during that time not one ephip- 
pium was produced. 
These experiments, however, and many others with similar results prove only that the 
mere stimulus of the presence of males is not sufficient by itself to cause the development 
of ephippia, but that other concurrent circumstances are necessary. 
It has been stated by most writers that the males and ephippia appear only at certain 
seasons: Zenkee, however*, has stated that the males may be found all through the 
year, and I have myself observed both males and ephippia from the beginning of May 
till the end of December, with only intervals here and there of a foAv days. Moreov er, the 
ephippial eggs laid in the spring, summer, and autumn, did not, as is often stated, remain 
undeveloped till the following spring, but at least in many cases were hatched u'ithout 
any great interval. 
I have only once, and then not very satisfactorily, been able to see the actual deposi- 
* Loc. cit. 
