518 CAROLINE BUELING THOMPSON 



many unlaid eggs. The wingless condition and active habits of 

 the third form of Termopsis have led many writers to refer to it 

 as a 'worker/ or at best as a Svorker-like' form, but because true 

 workers are sterile the term should not be applied to this invari- 

 ably fertile caste. Females are recognizable from males by the 

 larger seventh abdominal sternite; the styles, genital appendices, 

 are present in both sexes. The pale yellow anal cerci of the tenth 

 abdominal segment have frequently four segments, but sometimes 

 five, as in the first form. 



Internal anatomy. The brain (fig. 4, c) varies with the individ- 

 ual in size, but even in the largest specimens is smaller then that 

 of the first form, on account of the reduction of the optic lobes; 

 the mushroom bodies are large, but lack the curved surfaces of 

 the first form. The hypodermis of the frontal surface is not 

 differentiated to form a frontal gland in the specimens sectioned. 



The four intestinal caeca are of equal size as in the other repro- 

 ductive castes. 



The female reproductive system of a young third-form queen is 

 shown in figure 13. There are practically no differences in any 

 of the organs from those of a young first-form adult. A nearly 

 mature egg from an older third-form queen is shown in figure 14. 



The male reproductive system (fig. 17) shows a great increase 

 in size in this caste. The huge testes, t, consist of a multitude of 

 short rounded lobes ; the vasa def erentia, as seen in whole mounts, 

 are filled with spermatozoa, sj)., the tubules of the seminal vesicles, 

 sy, are very long, stout, and convoluted. The testes sectioned 

 were very young, though of large size, and most of the sex cells 

 were in the condition of spermatogonia and spermatocytes, 

 with no spermatozoa as yet developed. All of the whole mounts 

 of older individuals showed spermatozoa in the testes and vasa 

 def erentia. 



The fat-body is smaller in third-form individuals than in the 

 other reproductive castes, not always filling the abdominal spaces. 



