OSI6IN OF CASTES OF TERMTTES 129 



tinuing as the adult of the first form, with ancestral stmcture 

 and habits. If the third reproductive caste, with no wing pads. 

 is a true caste, it may be accounted for. according to this 

 hvpothesis: as a second mutant from the ancestral parent refH^> 

 ductive type. But. and I shall return again to this question, 

 I am by no means sure that the wingless reproductive forms 

 constitute a caste. Still later, the generalized worker-soldier 

 tyi>e difiFerentiated or spht up into the highly specialized sol- 

 dier caste and the primitive worker caste which more nearly 

 resembles the parent form. Both soldier and worker may mani- 

 fest their inherent variability by occasional fertility. Wheeler 

 ('07) remarks: "I venture to maintain that fertile workers occur 

 much more frequently in all groups of insects than has been 

 generally supp>osed. As this fertihty is merely a physiolc^cal. 

 state it has often been overlooked." 



The rare and occasional winged workers and soldiers might 

 be regarded as hybrids from one of the reproductive castes^ 

 with fertile workers or soldiers, or as fluctuating variations. 



The reproductive adults of the third form, or the reproductive 

 forms that are wholly devoid of wings, must next be considered. 

 These forms are of rare occurrence in the genus Leucotennes. 

 as stated above. There are three ix»ssibilities for the origin 

 of these wiagless and fertile individuals: first, this form may be 

 a true caste, a mutant thrown off from the ancestral reproductive 

 type: second, it may be a hybrid, from a worker and one of the 

 reproductive forms: third, the indi-viduals of this 'caste' may be 

 fertile workers. An investigation of the internal structure and 

 the development of this questionable caste is greatly needed. 



The next question to arise is. are these facts in the develop- 

 ment of L. flavipes in harmony with the facts observed in other 

 genera of termites? 



Bugnion has found in Eutermes lacustris that the soldier 

 m-mph is distinguishable at the time of hatching, that is. it is 

 predetermined. Unfortunately Bugnion did not report any 



' Mr. Snyder has informed me tiat thepe are no kno-sm insTances of fertile 

 or winged workers or soldiers in the genus Leacoxermes. 



JOrSXAJ. OF VOSPHOLOGT. VCL. 30. XO. 1 



