384 GEORGE T. HARGITT 
to heredity, that an examination of some of the assumptions 
on which the theories of heredity rest is not only of interest but 
more or less necessary. Weismann, who has been the great expo- 
nent of the uniqueness (one might almost say the sacredness) of 
the germ cells, based his hypothesis principally and primarily upon 
his work on the Hydromedusae. It has been found by Goette 
and others that many of his views on the place of origin of germ 
cells in hydroids, their place and manner of ripening, what he 
called the ‘germinal track,’ etc., are quite erroneous, but they are 
still referred to as bases for conclusions on other problems and 
theories. 
Since it was found that Campanularia flexuosa offered such an 
unequivocal answer to some of these very questions it has seemed 
to be worth while to make a careful study of it and the results are 
here set forth. 
MATERIALS AND METHODS 
The material was collected, some in 1908 in Great Harbor at 
Woods Hole, some in 1909 in Casco Bay, Maine, at South Harps- 
well. I wish to thank the directors of the biological stations at 
these places for the courtesies extended to me. The material 
so collected was killed in Zenker’s fluid, in Bouin’s picro-aceto- 
formol, in Mann’s picro-corrosive-formol, and in several of the 
other common killing mixtures. As noted in the earlier paper, 
it was found that material allowed to remain in alcohol for any 
length of time deteriorated somewhat, particularly as regards the 
finer details of the nucleus. When this was demonstrated the 
material not imbedded at once and preserved in paraffin was used 
sparingly or for comparison on grosser points of structure; the 
details here shown have all been worked out from material which 
was imbedded as soon as possible after being killed, in each case 
within two weeks after the capture of the material. Since then 
I have made a practice of imbedding the material within a few 
hours or a day after killing, with excellent results. As has been 
suggested by others (Smallwood ’09, C. W. Hargitt ’11) this 
is a very necessary precaution, since it does make a noticeable 
difference in the results. 
