252 SUMMARY OF CURRENT RESEARCHES RELATING TO 



with hunger, and perhaps also to some extent with the weather ; but the 

 author notes that there are favourable places for depositing the eggs, and 

 that the young forms migrate from these in bands seeking food. The 

 minuteness of the body is in itself an adaptation preventing the freezing 

 of the body-fluids. The hairs on the body and the dark colour may also 

 help. J. A. T. 



6. Crustacea. 



Nerves of Antennules Regenerated in Place of Eyes. — Curt 

 Herbst and H. Plessner (^rcA. EnfivicJclungsmech.,Wl(3,^2, 407-89, 

 11 pis.). When an antennule of Palsemoii or PaUnurus is regenerated 

 in place of an eye, bundles of nerve-fibres grow centripetally from the 

 antennule, enter the stump of the optic nerve, and traverse it to reach 

 the brain. In the stump of the optic nerve and the oculomotor nerve 

 there is a proliferation of cells forming the sheaths of the nerve-fibres. 

 The old optic nerve becomes an antennary nerve. In PaUnurus there 

 develop at the base of the optic stump large ganglion cells such as occur 

 normally at the root of the first antennary nerve. Some nerve-fibres 

 from the antennule lose themselves in the head, others enter the stump 

 of the oculomotor and reach the brain that way. The main passage 

 of the new antennary nerve is through the stump of the old optic, and 

 this explains how excitation of the new antennules results in reaction 

 movements the same as those which normally follow the excitation of 

 the eye-stalk. Herbst does not think that the brain directs the new 

 fibres, but there may be an attractive influence from the degenerating 

 nervous substance at the stump of the optic nerve. When the new fibres 

 reach the brain there may be a reaction from the brain influencing their 

 further development. J- A. T. 



Ceina egregia : an Aberrant Amphipod. — Charles Chilton 

 {Trans. New Zealand List, 1919, 51, 118-29, 25 figs.). An account 



Ceina egregia. Side view of male. 



is given of this aberrant form, one of the Talitridae. In many of its 

 characters it more or less resembles Hi/ale ; in some it approaches 



