Biologisches Centralblatt. 



Unter Mitwirkung von 

 Dr. K. Goebel und Dr. R. Hertwig 



Professor der Botanik Professor der Zoologie 



in Mtinchen, 



herausgegeben von 



Dr, J. Rosentlial 



Prof, der Physiologic in Erlangen. 



Der Abonnementspreis fur 12 Hefte betragt 20 Mark jahrlich. 

 Zu beziehen durch alle Buchhandlungen und Postanstalten. 



Die Herren Mitarbeiter werden ersucht, alle Beitriige aus deui Gesanitgebiete der Botanik 

 an Hcrrn Prof. Dv. Goebel, Miinchen, Luiseustr. 27, Beitriige ans clem Gebiete der Zoologie, 

 vg-1. Anatomie mid Entwickelungsgeschichte an Herrn Prof. Dr. R. Hertwig-, Muncheu, 

 alte Akadeniie, alle iibrigen an Herrn Prof. Dr. Rosentlial, Erlangen, Physiolog. Institut 



eiuseiiden zu wollen. 



Ed. XXXIY. 20. Juli 1914. Jj 7. 



In halt: Fuchs, The Effect of Abundant Food on the Growth of Young Ciona intestinalis. Mast, 

 L. J. Henderson on "The Fitness of the Environment". Karawaiew, Eine neue Weber- 

 ameise, Polyrhachis armata. le Guillou. - Stellwaag, Sperrtriebe am Kafei-thorax. 

 Haempel und Kolmcr, Ein Beitrag aur Hclligkeits- und Farbenanpassung bei Fischen. 

 Kruiielli, Ricerclie sugli adattamenti alia vita planctonica (I Gobidi platiL-toniciJ. Seitz, 

 Innere Sekreiton und Scliwangerschaft. Bekanntmachung. 



The Effect of Abundant Food on the Growth of Young 



Ciona intestinalis. 

 By H. M. Fuchs. 



(Mit 9 Figuren.) 



During the spring of 1913 a considerable number of experiments 

 were made to discover the optimum conditions for rearing Ciona 

 intestinalis. The work was done at the Zoological Station, Naples, 

 and was a preliminary to the breeding of the animals for certain 

 heredity investigations. In the course of the work an interesting 

 effect of the amount of the food supply on the growth of the young 

 Ciona was brought to light, and it is thought that the results are 

 worth recording now. 



For each rearing experiment the eggs of one individual were 

 artificially cross-fertilized by the sperm of another. The exact 

 methods employed, ensuring the absence of spermatozoa of any 

 other individual, and the consequent purity of the separate families, 

 will be described in full in a later paper dealing with the relative 

 effects and conditions of self- and cross-fertilization in Ciona in- 

 testinalis. It is unnecessary to go into the methods and precautions 

 here, since the purity of the different families reared does not affect 

 the point under discussion. The larvae were allowed to settle on 

 the walls of the bowls in which they hatched out of the eggs, and 

 XXXIV. 28 



