XXXJii, '22] ENTOMOLOGICAL NEWS 63 



arisen phylogenetically from the ancestral median ocellus 

 which is now lacking in the termites" (1916). 



Her most important paper is that dealing with the origin of 

 the castes of the common termite (1917). In it, after review- 

 ing the views held as to the influence of food on differentiation 

 of the various forms as well as the doubts expressed by others, 

 she produced evidence that there are visible internal differences 

 between the newly hatched young which are to develop into 

 the reproductive and non-reproductive members of the com- 

 munity respectively, although externally they are. all alike. 

 'Therefore the fertile and sterile types are predetermined at 

 the time of hatching," * * * * "My final conclusion is that 

 all termite castes are predetermined in the egg." She was care- 

 ful to point out the bearing of this discovery and the similar 

 observations of Bugnion (1912, 1913) on ''the greater ques- 

 tion whether the heritable bodily structure is determined by 

 extrinsic factors, such as food and environment, or by in- 

 trinsic factors within the germplasm." In two other papers 

 (1919. 1920) additional confirmatory evidence in support of 

 the germinal predetermination theory was furnished. In con- 

 junction with Mr. T. E. Snyder, of the United States Bureau 

 of Entomology, she discussed the question whether the phvlo- 

 genetic origin of termite castes (1919) could be referred to 

 continuous or discontinuous variations, without, however, 

 reaching a definite conclusion. 



Mr. Snyder has published a sympathetic notice of her abili- 

 ties as a teacher and an investigator in Science for January 13, 

 1922, which the present writer heartily endorses. His acquaint- 

 ance with her dates from her first appearance as a student at 

 the University of Pennsylvania and he has followed her work, 

 on the termites especially with the greatest interest and pride 

 in her achievements. Oh that she had lived longer and carried 

 out her plans for similar work on the honey bee ! 



PHILIP P. CALVERT. 



A list of Dr. Thompson's entomological papers follows: 

 1913. A Comparative Study of the Brains of three Genera of Ants, 

 with special reference to the Mushroom Bodies. Journ. Comp. 

 Neur., I'hila.. 23, 515-572. 



