220 Experimental Zoology 
that any fertilized egg may produce a fertile queen, and the 
amount of food supplied to the young larve determines the re- 
sult. If the old queen dies and young larve 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 larve 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.* 
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 
Barpiani, G. Sur la reproduction et l’embryonogie des Pucerons. Comp. 
Rendus, LXII. 1866. 
Mémoire sur la génération des Aphides. Ann. Sci. Nat. (5th), XI, 
XIV, XV. 1869-1872. 
BaARFuRTH, 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. Traité d’Insectologie. 1745. 
Born, G. Ueber Versuche von Salamandra maculata und Anguis fragilis 
ausserhalb des Leibes der Mutter aufzuziehen. Zool. Anz. II. 
1879 
CALKINS, % Studies on the Life-History of Protozoa, IV. Death of the 
A’ series. Conclusions. Jour. of Exper. Zool. I. 1904. 
Cakins, C., and Lies, C. Studies on the Life-History of Protozoa, II. 
The Effect of Stimuli on the Life-Cycle of Paramcoecium caudatum. 
Arch. f. Protistenkunde, I. 1902. 
‘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. 
