ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
293 
Notes on Adriatic Hydroids. — K. Babic ( Glasnik , Rev. Sci. Nat. 
Croatica , 1921, 33, 94-7, 3 figs.). Notes on Tubiclava lucerna Allman, 
Campanulina panicula Sars, Lafoea dumosa (Fleming), Gonothynea 
biciispidata(fi\&xk),tmdL some other forms, including a species of Laomedea 
with sixteen sharp denticles at the margin of the theca. J. A. T. 
Porifera. 
Restitution-bodies and Free Tissue-culture in Sycon.— Julian 
1 S. Huxley {Quart. Journ. Micr. Sci., 1921, 65, 293-321, 2 pis.). 
Mixture of cells of dissociated tissues of Sycon in normal proportions 
may lead to normal regenerates, like post-larval Sycon , with spicules, 
osculum, and pores. There is a sorting-out of the dermal and gastral 
oells. The former produce a single-layered epithelium, below which 
spicules are subsequently formed, the latter a 'central mass which becomes 
a hollow one-layered sac. In the cavity of this sac the cells put forth 
collars and flagella. Their fate is not a function of their position in the 
whole, but of their nature. Free tissue-cultures of collar cells form 
spheres, which live for a considerable time, but do not regenerate or 
form spicules. All grades from these to masses with an excess of dermal 
cells may be formed. Restitution-masses may cohere and unify. 
Spontaneous segmentation into spherules may also occur in unfavourable 
conditions. The spherules usually secrete a gelatinous covering. They 
may differentiate a normal dermal epithelium. The bulk of the 
; component tissue (presumably choanocytes) usually separates into its 
constituent cells after a time. Dedifferentiation of all cells takes place 
after dissociation of tissues, but it does not lead to a totipotent condi- 
tion. J. A. T. 
Adriatic Sponges. — K. Babic {Glasnik, Rev. Sci. Nat. Croatica, 
1921, 33, 77-93, 9 figs.). A report on Adriatic Monactinellida 
(60 species) and Tetractinellida (22 species). Of these 82 forms, 
25 Monactinellids and 7 Tetractinellids are new for the Adriatic, and 
7 Monactinellids are new species. J. A. T. 
Protozoa. 
Reactions to Light in Amoeba. — Harry T. Folger {Proc. Amer. 
Soc. Zool. in Anat. Record, 1922, 23, 128). Amoeba reacts to sudden 
increase in illumination by complete cessation of movement, the time 
becoming shorter as the intensity increases, but not in precise inverse 
proportion. The reaction-time may be divided into a stimulation-period 
during which the amoeba must be exposed to light if there is to be a 
response, and a latent period during which exposure is not necessary. 
There may be considerable changes in the length of the latent period. 
The stimulation-period varies inversely with the intensity of illumina- 
I tion. J. A. T. 
Influence of Temperature on Rate of Locomotion in Amoeba. — 
A. M. Schwitalla {Proc. Amer. Soc. Zool. in Anat. Record , 23, 128-9). 
At a constant temperature there are alternate periods of acceleration 
and retardation in the rate of locomotion — phases of a locomotor rate- 
