Можно предположить, что слабо действующий с. allatum последнего воз- 

 раста способен выделять такое количсетво ЮГ, которое достаточно для того, 

 чтобы тормозить секрецию с. allatum хозяина. Но он не способен в доста- 

 точной степени и в необходимый срок обеспечить концентрацию гормона, 

 необходимую для возникновения нормального 5-ого возраста. Выше ука- 

 занная аналогия с действием тироксина на функцию щитовидной железы 

 свидетельствует, как нам кажется, о более широком значении гипотезы, 

 подтвержденной нашими опытами. 



SUMMARY 



As shown by Pflugfelder (1937) and other authors, the implantation of an active 

 corpus allatum results in a more or less advanced atrophy of the acceptors gland. It has 

 been suggested by Novak (1959), that this effect of the implanted gland consists in the 

 preventing the diffusion of the juvenile hormoiae (JH) from the host corpus allatum 

 into haemolymph, supposing that the JH concentration ia the blood, produced by the 

 implanted corpus allatimi has surpassed that in the cells of the host corpus allatum. 

 The authors attempted to test this possibility through biometrical research of the c. 

 allata of the Pyrrhocoris apterus (L.) imagoes in the 3rd, 6th and 9th day of the imaginai 

 life, having been implanted immediately after the imaginai moulting with an active с 

 allatum. As controls specimens implanted 5th day after moulting have been used. The 

 preliminary results of the experiments continuing so far seem to prove the mentioned 

 hypothesis. They are being controled by similar experiments in the IVth (one but last) 

 larval instar of the silkworm {Bombyx mori L.). A full confirmation of the hypothesis 

 would make possible some interesting conclusions as to the question of phylogeny of the endo- 

 crine function in general. 



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