88 ]\rE. LUBBOCK’S ACCOTJKT OF THE TWO IMETHODS OF EEPEODrCTIOX 
which I have in this paper called “ agamic,” certainly do not require to be fertilized in 
the ordinary manner; and as these two sorts of eggs only, i. e. the agamic and the ephip- 
pial, are produced when the males are tolerably numerous, and may often be obsers ed in 
coitu, it follows either that impregnation is necessary for the ephippial eggs, or, which in 
the present state of our knowledge seems less probable, that one or both sorts of eggs 
may be impregnated, but that neither of them require to be so. 
Whenever ephippia were produced, as a general rule, I could also find males ; and at 
the time when there were most ephippia, the males were most numerous ; but once when 
there were a good many ephippia, I could, after careful search, find only one male ; and 
though I continued every morning for several days to look for males, I could not find 
another specimen, although at the same time ephippia were being developed. In order 
to determine, if possible, whether ephippia were ever produced without impregnation, I 
had taken on the 13th of November ten specimens with black ephippia and placed them in 
a tumbler. These all cast their ephippia ; seven of them had then a brood of agamic 
eggs, three produced ephippia, which, however, might have resulted fi’om impregnation 
ha-sdng taken place before I isolated them. On the 29th these two had cast their 
ephippia, and yet after this three ephippia were developed, which were cast respectively 
on the 7th, 10th and 17th of December. 
Again, on the 7th of December I placed by themselves eight specimens mth black 
ephippia : these all cast their ephippia, and had each a brood of agamic eggs, after which, 
i. e. on the 17th, two more ephippia were visible. 
Unless there is a spermatheca in which the spermatozoa can remain in a healthy state, 
so as to fecundate successive broods, which I do not believe to be the case, these experi- 
ments prove that ephippia can be produced without male influence. I only, however, 
met with seven instances*, though I have had at least 400 broods of agamic eggs pro- 
duced by females kept separate from males. 
Moreover, it is not surprising that ephippia should be sometimes so produced, because 
we know that throughout the animal kingdom eggs are produced sine concubifu, althoiigh 
such eggs are usually barren. 
Finally, in fifty cases in which I watched at intervals of a few hour’s the early stages 
of egg-development, the collection of brown-coloured granules round a germinal vesicle 
(which is the commencement of the ephippial egg) took place in forty-three ; and in 
seventy in which I watched the subsequent stages it disappeared in all excepting three. 
I believe, however, that the seven above-mentioned apparently exceptional cases arise 
only from the animals not having been examined at the right time, and that the early 
stages of the ephippial egg are always passed through. Something, therefore, must 
usually be wanting, which is necessary to the further development of it, and I am at a 
loss to imagine what this want can be, unless it is the absence of impregnation. 
We need not long doubt why the Baphnia has been provided uith this unusual appa- 
* Up to the present time (May 26) these ephippia have produced no young, though other ephippial eggs 
have hatched in the meanwhile. 
