STUDIES ON THE NERVOUS SYSTEM OF ORUSTACEA. 461 
Studies on the Nervous System of Crustacea. 
By 
Edgar J. Allen, B.Sc.Lond. 
With Plates 35 and 36. 
I.—Some Nerve-elements of the Embryonic Lobster. 
Tue observations to be recorded in the following paper were 
made at the Laboratory of the Marine Biological Association 
in Plymouth, with the assistance of a grant made me by the 
Government Grant Committee of the Royal Society. My 
thanks are due to the officials of the laboratory for their con- 
stant support, to the committee of the British Association, 
Robert Bayly, Esq., of Plymouth, and Professor E. B. Poulton, 
for supplying me with nominations to the laboratory, and to 
Professor Weldon for advice and help. 
The remarkable results obtained by recent investigators of 
the nervous system of Vertebrates, by making use of embryos 
and very young animals, led me to try a similar plan in an 
attempt to obtain an insight into the structure of the Crustacean 
nervous system. The two methods used have been Ehrlich’s 
methylene blue method, as modified by Biedermann! and 
Apathy,” and the rapid method of Golgi, as modified by Ramon 
y Cajal, Kolliker, and Nansen. Of these, up to the present, 
1 Biedermann, “Uber den Ursprung und die Endigungsweise der 
Nerven in den Ganglien wirbelloser Thiere,” ‘Jena. Zeitschr.,’ Bd. xxv, 
1891. 
2 Apathy, ‘ Erfahrung in der Behandlung des Nervensystems fiir histolo- 
gische Zwecke. I. Methylen blau,” ‘ Zeitschr. wiss, mikr.,’ Bd. ix, 1892. 
