1881.] NATURAL SCIENCES OP PHILADELPHIA. 51 



two-thirds the usual spherical abdomen. What the result would 

 have been had the}'' lived the entire year, and how long it would 

 have taken them to attain the rotund condition can only be 

 guessed.^ 



6. Among the callows, or young ants, collected, I could find no 

 evidence at all of a separate honey-bearer caste. Among the 

 larvae there were some large, broad grubs, that differed much from 

 the others, which I supposed to be queen-grubs. I was not able 

 to hatch these and the cocoons, and observe results, a process 

 which would probably determine the whole inquiry. The cocoons 

 collected were all of three sizes, corresponding in length to the 

 workers, major, minor and dwarf or minim as this smallest caste 

 might perhaps be called. 



Y. A comparison of the workers* with the honey ^bearer shows 

 that there is absolutel}' no difference between them except in the 

 distended condition of the abdomen. The measurements as to 

 length and size of head, length of legs and thorax are precisely the 

 same. This appears to be true also, of some of the smaller rotunds 

 and the minors. 



My conclusion from the above facts is that the worker majors, 

 for the most part, and sometimes the minors, are transformed by 

 the gradual distention of the crop, and expansion of the abdomen, 

 into the honey-bearers, and that the latter do not compose a dis- 

 tinct caste. ^ It is probable, however, that some of the majors 

 have a special tendency to this change by reason of some peculiar 

 structure or form of the intestine and abdominal walls. 



8. Finally I undertook an anatomical comparison of the honey- 

 bearers and workers. I made a large number of dissections, which 

 were carefully studied and compared, and these observations 



^ Some observer upon the field might readily take up these and other ex- 

 periments and carry them to a satisfactory conclusion. There are invalids 

 at Colorado Springs and Manitou, who might follow the admirable example 

 of the late Mr. Moggridge at Mentone, and find both enjoyment and pro- 

 longed life in some such studies. 



' I am glad to be confirmed in this opinion by Dr. Aug. Forel, to whom 

 I early sent specimens and notes, and who has shown a gratifying interest 

 in these studies, and has cordially aided them by valuable suggestions. 

 See a communication to the Morphologico-Physiological Society of Munich, 

 in Aerztlichen Intelligenz-Blatte, Jan'y, 1880. 



