MATURATION OF OVUM OF ALCYONIUM DIGITATUM. 495 
at all, visible. This uncertainty made the work far more 
laborious than it would have been in the case of Hchinoderm 
egos, of which, under even the most unfavourable conditions, 
scarcely a single egg fails to be fertilised. The ova were 
highly sensible to temperature, and to the degree of salinity 
of the water. It was found necessary to make arrangements 
whereby the eggs could be kept cool by a stream of running 
water, with as little evaporation as possible. ‘To one accus- 
tomed to the ease with which the eggs of Hchinoderms can 
be dealt with the perverseness of the ovum of Alcyonium 
was a most unwelcome change. Nevertheless, I have reason 
to believe that the fault lay more with the spermatozoa than 
the ova, and that, had I been able to obtain really ripe male 
colonies, far fewer failures would have resulted. 
In consideration, therefore, that it would be unwise to 
publish the results of an investigation only partially success- 
ful, I have waited until now in the hopes that some zoolo- 
gist with more time at his disposal, and with more luck or 
skill than myself, might attack the problem and thoroughly 
bring to ght what my own incomplete work has shown 
to be a strange process. I have, however, come across 
no published records of any such research. But I have at 
least been able to confirm Professor Hickson’s observation 
as to the disappearance of the nucleus before fertilisation,! 
and thrown some light on previous and subsequent stages. 
Though we realise that much yet remains obscure, we feel 
justified in bringing our observations to the notice of zoolo- 
gists, owing to the fact that C. W. Hargitt,? in his paper on 
the early development of Pennaria tiarella McCr., has shown 
that the results I have obtained are by no means without 
parallel as far as the disappearance of the female pronucleus 
(not oosperm) goes. Not only in other Celenterates? but 
1 Hickson has examined alone nearly fifty complete series of sections and 
found no trace of a nucleus. 
2<The Karly Development of Pennaria tiarella McOr.,’ ‘Arch. fiir Ent- 
wick, mechanik der Org.,’ Band xviii, Heft 4. 
3 V. Koch, “Die Gorgoniden des Golfes von Neapel,” ‘Fauna u Fiora 
Mon.,’ xv. 
