718 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
times expressed by him that there is no more reason for regarding the 
chlorophyll-corpuscles of Hydra viridis and of Spongilla viridis as 
symbiotic Algae than there is for so regarding the chlorophyll-corpuscles 
of a buttercup. Whether there is sufficient reason for the latter is a 
different question, and one not to be hastily dismissed. 
It is obviously necessary to distinguish for the present the strongly 
marked unicellular parasites of Eadiolaria and Anthozoa — the “ yellow 
cells ” — from the green cells of Convoluta and the chloroplasts of various 
forms. 
Marine Invertebrate Fauna near Dublin.* — Messrs. G. Y. and A. 
F. Dixon have a report of their observations on various marine animals. 
They find that the number of oesophageal grooves in Metridium dianthus 
is not constant, as it is not unusual to find two. In the process of 
reproduction by fission it would appear that the parts separated from the 
parent are not in any way specialized ; in some cases, however, there 
have been appearances of the formation of a bud. In this species one 
tentacle sometimes becomes greatly elongated and arches over the other 
tentacles ; it ultimately returns to its normal condition, when it is not 
distinguishable from the others. One large example, while roving 
through the tank, stumbled across a fine specimen of Bunodes verrucosa , 
over which it poured out such an enormous number of acontia that the 
Bunodes drooped more and more until it died. M. dianthus, like 
Actinia equina, has the power of floating on the surface of the water, 
base upwards. The authors have paid particular attention to the- 
arrangement of the mesenteries in this and other species, on which they 
have notes. Variations in coloration are also carefully noted. 
Peachia hastata appears to have no stinging cells, or weak ones only, 
for gobies and other small fish rest placidly on it. Its ova were seen to 
be small spheres, furnished with short, stiff hairs or bristles, which 
stick out straight from the surface, and do not move like cilia. Gosse’s 
P. undata is probably an immature P. hastata. 
The authors justly remark that Gosse’s description of Zoanthus Couchii 
is very general, and includes many forms that are or might be referred 
to distinct species — one for example is the Epizoanthus Wrightii shortly to 
be described by Prof. Haddon. 
Of Crustacea the authors speak only of Hyas araneus, and express 
their belief that its habit of clothing itself with corallines, shells, and 
other foreign bodies is useful to it by helping to furnish it with the 
means of catching its prey. If the environment of the crab is changed 
its dress becomes altered to suit it. 
The grace of the motion of Eledone cirrosa as it propels itself back- 
ward by ejecting water from the funnel is thought to be due to the 
position in which it folds its arms, always keeping the base of one on 
either side sharply projecting, so as to make a pair of lateral keels. 
Origin and Mode of Termination of Serves in Ganglia of Inver- 
tebrate. | — Herr. W. Biedermann gives first an account of the results of 
his investigations on Him do medicinalis. Of the fibres that form the 
commissures two that are broad generally exhibit a very distinct fibrillar 
* Proc. Roy. Irish Acad., ii. (1891) pp. 19-33. 
t Jcnaiscke Zeitschr. f. Naturwiss., lv. (1891) pp. 428-66 (1 pi.). 
