26 W. BLAXLAND BENHAM. 
The specimen II, which was mounted entire, is a male, and 
the spermatozoa exist only in the hindermost part of the body. 
It would appear, therefore, that the gonads make their appear- 
ance simultaneously over a certain stretch of the body, com- 
mencing at the hindermost region; that as they ripen this 
region begins to be constricted off from the rest of the body. 
A second tract now commences to ripen, and in its turn becomes 
marked off from the non-sexual anterior region of the body ; 
and so the process goes on up to the point of origin of the 
proboscis. 
Further, each such region may become restricted into two 
(or more?) pieces ; and it will be very interesting to ascertain 
whether this segmentation goes any further than in the speci- 
mens to hand. It is possible that the segmentation of this sexual 
region of the body, which is already beginning in our specimens, 
may ultimately become so far repeated that each “‘ segment ” 
will contain only a single pair of ovaries. In that case we 
should have a strong case in support of Hubrecht’s theory of 
segmentation, as elaborated in his ‘ Report on the Nemertines 
of the Challenger Expedition.’ 
However that may be, we have in this Carinella what 
appears to be an undoubted preparation for the spontaneous 
subdivision of the sexual region of the body into a number of 
isolated portions, and this subdivision is due to the develop- 
ment of the gonads, and is thus directly related to the pro- 
pagation of the species. 
We have yet to learn whether each of the pieces so isolated 
will produce a new head; but it appears to me a needless 
assumption that this would happen. As each “segment” 
drops off, the tissues after decomposition might set free the 
generative products; but since genital ducts (fig. 3, g.d.) are 
already forming, and are in the hindmost segments nearly 
completed, it appears that the segments live an independent 
life for some time after separation. This fact, therefore, mili- 
tates against the idea of any greatly extended “‘ segmentation.” 
Anatomical.—The Nemertine which forms the subject of 
the present contribution exhibits one or two points of interest 
