320 JULIAN S. HUXLEY 
11. The flagella of collar-cells are adhesive. 
12. Larvae may become embedded in the restitution-masses ; 
they are gradually resorbed. 
13. Restitution-masses, if brought into contact, will cohere. 
The irregular masses thus produced gradually round up and 
become unified. 
14. Mechanical shock causes a contraction of both dermal 
and choanocyte blow-outs, and a retraction of the collars and 
partial retraction of the flagella in the latter. 
15. A peculiar small finger-shaped amoebocyte (‘ finger- 
cell’) is numerous in normal sponges and restitution-masses. 
These cells are arranged in a remarkable manner below the 
dermal epithelium of dermal blow-outs. 
16. Spontaneous segmentation of restitution-masses into 
small spherules may take place, apparently in unfavourable 
circumstances. The spherules usually secrete a gelatinous 
covering. They may differentiate a normal dermal epithelium. 
The bulk of the component tissue (presumably choanocyte) 
usually separates into its constituent cells after a time. 
17. A type of restitution-body with dark central mass is 
deseribed. 
18. Dedifferentiation of all cells takes place after dissocia- 
tion, but does not lead to a totipotent condition. 
New CoLureGe, Oxrorp. 
October 1920. 
LITERATURE List. 
Adami and McCrae (1914).—‘ Text-book of Pathology ’, Macmillan, 
London, 1914. 
2. Child (1902).—‘‘ Studies on regulation. I”’, ‘ Arch. f. Entw.-Mech.’, 15, 
1902, pp. 187, 355. 
3. —— (1915).—‘ Individuality in Organisms’, Univ. Chicago Press, 
1915 (with references to previous literature). 
4. De Morgan, W., and Drew, H. (1914).—* A study of the restitution 
masses formed by the dissociated cells of the Hydroids Antennularia 
ramosa and A, antennina’’, ‘Journ. Mar. Biol. Assoc., Plymouth ’, 
10, 1913-15, p. 440. 
5. Gray, J. (1920).—‘* The effects of Ions upon Ciliary Movement ’’, 
‘Quart. Journ. Micro. Sci.’, 64, 1920, p. 345. 
6. Holmes, J. (1914).—‘* The behaviour of the Epidermis of Amphibians 
when cultivated outside the body”, ‘Journ. Exp. Zool.’, 17, 
1914, p. 281, 
—= 
