ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 4G1 



system, or by making compensatory movements, or otherwise. The 

 animal experimented with was Garcinas msenas, but analogous experi- 

 ments with other forms are being made. 



Regeneration in Atya serrata.* — E. Bordage has given reasons for 

 believing that Atya serrata Spence Bate has arisen by mutation from 

 Ortmannia alluaudi Bouvier, and he offers an interesting corroboration 

 of this view in the fact that removal of the chelipeds is followed by a 

 regeneration after the Ortmannia type, what he calls a " hypotypic 

 regeneration." 



Bathynomus giganteus.f — R. E. Lloyd gives an account of the 

 internal structure of this large Isopod, and describes the sexually mature 

 males. The specimen dissected was 193 mm. in length and 89 mm. in 

 breadth. The hepatopancreas is quite different from that of other 

 Isopods. It consists of three pairs of elongated glandular organs, each 

 of a simple racemose type. This is probably correlated with the large 

 size of the animal, for the minute structure is like that of the simple 

 tubular glands of smaller Isopods. The author has been able to give a 

 full description of the nervous system and of the internal skeleton of 

 the head. There are nearly three thousand facets in each eye. 



" The large vitrellas, v hich are remarkably clear and translucent 

 the well-developed black pigment, which not only separates these lenses 

 but spreads out and covers them peripherally like an iris, and the well- 

 developed, pigmented terminations of the retinula cells, all point to the 

 conclusion that the eye of Bathynomus is a useful, light-perceiving 

 organ. This fact lends support to ' the theory of abyssal light,' for 

 Bathynomus is essentially a deep-water form which does not seem to be 

 a recent emigrant from shallow waters." 



The eggs are 11 mm. in diameter — probably the largest recorded 

 Crustacean eggs. The memoir includes among its fine illustrations an 

 interesting photograph of a living female sweeping the water with its 

 pleopods — a movement which secures aeration of the blood in the 

 peculiar branchial tufts. 



Colours of Hippolyte varians.J — Romuald Minkiewicz has evoked 

 a great variety of coloration by keeping the animals in a glass aquarium 

 with the floor and walls covered with paper of the desired colour. 

 He got simple colours — red, yellow, and blue ; and mixed colours — 

 orange, olive, violet, brown, green. Some of these colours — bright 

 yellow, blue, and violet — do not occur in the natural environment of 

 seaweed ; and the author concludes from this that the " synchromatic 

 plasticity " of the chromatophores is not due to natural selection, but is 

 a capacity of a primary order, directly dependent on external chromatic 

 factors. 



A floor of blue and a floor of white both produce contraction of all 

 the chromatophores and a blue coloration. The changes are produced 

 on adults as well as on the young. Any variety can be changed into any 

 other. 



* Comptes Rendus, cxlviii. (1909) pp. 47-50. 



t Memoirs Indian Museum, i. (1908) pp. 81-102 (4 pis. and 8 figs.). 



% Comptes Rendus, cxlvii. (1909) pp. 943-4. 



