REPORT OF THE COUNCIL. 125 



]\Ir. Crawshay has since the completion of this work been engaged 

 with considerable success in experimental work on rearing copepods 

 and other plankton animals in the Laboratory, with a view to working 

 out the details of their life-histories, a subject upon which very much 

 remains to be done. 



In addition to extending the general faunistic records of the Plymouth 

 neighbourhood Mr. J. H. Orton has been specially studying the rate of 

 growth of invertebrates. A large collection of material and of data 

 has been brought together, and an important contribution to our 

 knowledge of this comparatively un worked subject is anticipated when 

 the work is reported upon. 



Mr, K. S. Clark is continuing the investigations on the mackerel 

 fisheries off the Cornish coast which were commenced some years ago 

 by the Director and Mr. Bullen. There seems reason to hope that a 

 thorough investigation of the causes which induce the migrations of 

 this fish may make it possible to assist the fishermen in finding the 

 shoals. 



The work of Messrs. Shearer, De Morgan and Fuchs, who have 

 been further assisted by Messrs. J. G-ray and L. Doncaster and Miss 

 D. Jordan Lloyd, on the hybridization of Echinoids and the rearing of 

 parthenogenetic echinoderm larvae, has been published in a number of 

 papers in the Quarterly Journal of Microscopical Science, which have 

 attracted considerable attention. 



Mrs. Matthews has been investigating the development of AUyonium 

 and has been able to obtain all stages from the fertilized egg to the 

 fixed polyp in considerable numbers. 



Mrs. Sexton and Mrs. Matthews have been studying a species of 

 brackish-water Gammarus with a view to determining the nature of 

 the variations in structure or appearance which are brought about by 

 changes in the conditions under which the animals live. They have 

 succeeded in rearing five generations in about six months, and they 

 now have the animals living and breeding both in entirely fresh water 

 and in sea-water of normal salinity. 



Published Memoirs. 



The following papers, either wholly or in part the outcome of work 

 done at the Laboratory, have been published elsewhere than in the 

 Journal of the Association : — 



Doncaster, L., and Gray, J. Cijtological Observatioiit< on the Early Stages of 

 Segmentation of Echinus Hybrids, (^uait. Journ. Micr. Sci., vol. 58, 1912-13, 

 pp. 4S3-509. 



Fuchs, H. M. On Echinoderm Hi/hridisatiun. Kept. Brit. Af^soc. Adv. Sci., 1912. 



