320 Experimental Zoology 



that any fertilized egg may produce a fertile queen, and the 

 amount of food supplied to the young larvae determines the re- 

 sult. If the old queen dies and young larva? are present that are 

 not more than a day or two old, the workers can produce one or 

 more new queens by feeding the young grubs on the royal jelly. 



Leuckart found that the food of the young larvae of queens and 

 workers is the same for the first three days and then is changed 

 for the worker while the queen grub continues to be fed with 

 the same food rich in honey. At this time the female genital 

 organs appear, so that if the weaning of the worker grub does 

 not take place promptly, any excess of the royal jelly may cause 

 the ovaries to continue their development and produce a fertile 

 worker. 



In the bees all the workers are females with undeveloped 

 sexual organs. They have all the marks of perfect insects in 

 other respects, and cannot, therefore, be said to be neotenic. 1 

 The males or drones develop from unfertilized eggs, and their 

 characters are not affected by the kind of food they receive, 

 except that a drone fed on royal food may become unusually 

 large. 



LITERATURE, CHAPTER XIX 



BALBIANI, G. Sur la reproduction et 1'embryonogie des Pucerons. Comp. 



Rendus, LXII. 1866. 

 Memoire sur la generation des Aphides. Ann. Sci. Nat. (5th), XI, 



XIV, XV. 1869-1872. 

 BARFURTH, D. Versuche ueber die Verwandlung der Froschlarven. Arch. 



mikr. Anat. XXIX. 1887. 



BOAS, J. E. V. Ueber Neotennie. Festscher. f. Carl Gegenbaur. 1896. 

 BONNET, C. Traite d'Insectologie. 1745. 

 BORN, G. Ueber Versuche von Salamandra maculata und Anguis fragilis 



ausserhalb des Leibes der Mutter aufzuziehen. Zool. Anz. II. 



1879. 

 CALKINS, C. Studies on the Life-History of Protozoa, IV. Death of the 



A series Conclusions. Jour, of Exper. Zool. I. 1004. 

 CALKINS, C., and LIEB, C. Studies on the Life-History of Protozoa, II. 

 The Effect of Stimuli on the Life-Cycle of Paramcecium caudatum. 



Arch. f. Protistenkunde, I. 1902. 



1 In this case it is the germ -cells that fail to develop, while the body tissues 

 pass over into the adult condition. In a sense this is the converse of neotenia. 



