170 



I am indebted to the courtesy of Messrs. Macmillan & Co., the 

 publishers of the "Cambridge Natural History" now in course of 

 issue, for the use of the cliche for printing our illustration. The 

 materials, however, from which the draAvings were made were supplied 

 from the Royal Botanic Gardens, Trinidad, to Dr. D. Sharp, the 

 Editor, who has kindly afforded us assistance in making observations 

 by sending us valuable suggestions. 



Atta octo8j)inosa has no "soldier" form in its nest, and the 

 qvxeens and workers are much smaller than the like forms in the nest 

 of A. cepTialotes, and their colour is a lighter red. In some of the 

 nests of the smaller species of Fungus-growing ants the workers are 

 all of one size, and the winged male and female forms are only 

 slightly larger. In Trinidad the winged forms of A. cephalotes and 

 A. octospinosa emerge from the nest about May or June ; when 

 marital functions are carried on, new nests are formed, the males 

 perish, and the fertilized queen seeks a suitable home. It is not how- 

 ever, clearly shown as yet, whether the queen alone is capable of 

 forming and maintaining a nest until she has reared sufficient progeny 

 to take the work off her hands, but it is strongly indicated that she 

 is able to do so. It is however quite clear that three or four worlers 

 and nurses can start a new colony without the intervention or aid of 

 a queen, as this has been proved by experiment at the Gardens. It is 

 also clear that others besides the Queen can produce fertile eggs, as it 

 has been seen from the experiments we have carried on, that a colony 

 is capable of raising all the forms from eggs laid — when a Queen is 

 not present — either by fertile workers, or by individuals which are 

 enabled to carry on the extension of a colony by Parthenogenesis. 



An egg on being laid is taken charge of by the nurses, under whose 

 care it passes through its larva and pupa stages, a process which takes 

 about 50 or 60 days. This period is stated, for in a nest under daily 

 observation we noted that an egg passed through every stage in fifty- 

 seven (57) days. When the egg hatches it becomes a larva or " worm," 

 during which time it is diligently and regularly fed by the nurses 

 until it reaches the pupa stage. 



In the pupa stage, it takes no food, but remains quite dormant 

 and when ready to emerge, it is again waited upon by the nurses Avho 

 can be seen to subject the insect to what may be termed a system of 

 massage. Numbers of them can at this period be seen assisting the pupa? 

 to get rid of their pupa cover or blanket, after which they can be 

 seen to take the various parts of the body in succession, and by 



