1895.] Embryology. 1125 
We are probably not far wrong in concluding that conjugation is 
essentially the same in Allolobophora fetida and Lumbricus terrestris. 
In addition to filling the sperm receptacles of the other worm con- 
jugation commonly leaves a trace in the form of theso-called spermato- 
phores, or penis of Hering and older writers, which may here receive 
attention less from their intrinsic value than from their bearing, though 
it be slight, upon the important suggestion advanced by Professor Whit- 
man namely that spermatophores might have been the original means 
of transferring sperm and only later superceded, in most animals, by 
localized organs for transmission. Though in the earthworms the 
foreign sperm is discharged from the receptacles when the eggs are laid 
and fertilizes them outside the body it might be supposed that these 
spermatophores in question were remnants of a formerly useful 
apparatus for putting sperm from one animal into the other, such as is 
found in some leeches. In the brandling, however, the indications seem 
rather to favor the idea that the spermatophore here is in a sense 
accidental and of no historical value so that it cannot be relied upon 
in extending the condition found amongst leeches to other groups, even 
if related, 
When conjugating brandlings are separated we often find upon one 
or the other or both such spermatophores as are indicated in fig. 3. 
They are conspicuous white specks that soon turn yellow-brown though 
preserving a milk-white central elevation. 
When pulled off from the epidermis, to which it adheres quite firmly 
at first, each is a homogeneous membrane or hardened secretion with a 
central cavity full of ripe sperm that moves when crushed out. 
In a section of such a spermatophore attached between two rings we 
see, in figure 4, that it is very closely attached to the epidermis and that 
it ends abruptly, in fig. 3 it is seen to have a ragged edge and may also 
present outlying bits separately attached to the skin. The contained 
sperm lies in layered masses as if ejected into a stiffening jelly ; more- 
over this mass is not entirely closed in as the section, fig. 4, would indi- 
eate but lies in a pit or pouch that opens at the top, in other sections, so 
that the sperm may be squeezed out in a fresh specimen. The sperm- 
atophore is thus a mass of sperm lying in an irregular cup of some 
tough secretion that is spread out on the skin and stuck to it. 
Of 220 live brandlings taken at the conjugating season of the year 
84 had spermatophores attached at about the 22nd ring of the body. 
Generally there are two sometimes but one, generally they are attached 
so as to cover the groove between two rings as in fig. 4 but often they 
are on the face of a ring as in fig. 3. 
