546 General Notes. 
upon development at one period might only retard such features 
as were then commencing to develop; and those which were al- 
ready too far advanced, and such as had practically no existence, 
would not be effected. Thus the other unaffected features would 
continue to develop until maturity towards those of the parents, 
while the feature which had been aborted would remain stationary, 
only maturing with the preparental feature, by correlation, at the 
proper time, and the result would be the form of Z z + the colors 
a=Z 1a—Eugene N. S. Ringueberg. 
same, or nearly the same, conditions of existence, would form no 
gemmules, as these would be superfluous, I applied by letter to 
Dr. Joseph, who forwarded some preparations to me, ene s 
same time kindly wrote, among other things, as follows: pees 
supposition that no formation of gemmules takes place nee 
for neither in September nor in April did I find any. of 
people may perhaps think that the Spongille of the Siac 
Gurk were not descended from ordinary Spongille, but “6 
from Monaclinellidz of salt water, perhaps at a time W r 
waves of the Tertiary sea eroded the grottoes of Carnio a 
Friuli. This would have much more probability than the mee 
sition that in consequence of uniform conditions of existence, 
dependent upon the seasons, retrogression as re rds 
mules has occurred in Spongilla stygia. 
N ABLE NERVOUS STEM T 
EW WORM WITH A REMARK a worm which 
A. A. W. Hubrecht describes under the name © 
nervosum. He gives a general accoun 
bly a sucker. No traces of sexual, excretory, OF ve three 
were found. The epidermis is thin The me verse or cit 
layers, a thick external longitudinal, a middle pis 
cular, and an internal longitudinal layer, various y 
It consists (1) of a fine network of delicate filaments, f (2) of S 
