PROBOSCIS OF PHORMIA REGINA — DETHIER I73 



is eventually routed to the same effectors. Similarly, the existence of 

 contralateral inhibition (cf. Dethier, 1953) is not too surprising in 

 view of the fact that unilateral sensory stimulation under normal 

 circumstances (as, for example, one labellar hair) brings about very 

 effective bilateral motor activity. 



In addition to the balance which is accomplished by central integra- 

 tion, it has recently been demonstrated by electrophysiological meth- 

 ods (Hodgson et al., 1955) that there is a measure of peripheral 

 integration within a single chemoreceptor hair. Stimulation of one 

 neuron of a labellar hair, with sugar for example, affects the nature 

 of the discharge occurring in the other (rejection) neuron. Con- 

 versely, stimulation of the rejection neuron affects the nature of the 

 discharge from the acceptance neuron. These findings have recently 

 been confirmed in our laboratory. 



LITERATURE CITED 



Dethier, V. G. 



1953- Summation and inhibition following contralateral stimulation of tarsal 

 chemoreceptors of the blow fly. Biol. Bull., vol. 105, pp. 257-268. 



1955. The physiology and histology of the contact chemoreceptors of the 



blow fly. Quart. Rev. Biol., vol. 30, pp. 348-371. 

 1957- Chemoreception and the behavior of insects. Survey of Biological 

 Progress, vol. 3, pp. 149-183, Academic Press, N. Y. (ed. H. Bent- 

 ley Glass). 

 Dethier, V. G., and Bodenstein, D. 



1958. Hunger in the blowfly. Zeitschr. Tierpsychol., vol. 15, No. 2, pp. 

 129-140. 

 Dethier, V. G., and Chadwick, L. E. 



1947. Rejection thresholds of the blowfly for a series of alipathic alcohols. 

 Journ. Gen. Physiol., vol. 30, pp. 247-253. 

 Dethier, V. G. ; Evans, D. R. ; and Rhoades, M. V. 



1956. Some factors controlling the ingestion of carbohydrates by the blow 



fly. Biol. Bull., vol. iii, pp. 204-222. 

 Frings, H. 



1946. Gustatory thresholds for sucrose and electrolytes for the cockroach, 

 Periplancta americana (Linn.). Journ. Exp. Zool., vol. 102, pp. 

 23-SO. 

 Frings, H., and O'Neal, B. R. 



1946. The loci and thresholds of contact chemoreceptors in females of the 

 horsefly, Tabanus snlcifrons Macq. Journ. Exp. Zool., vol. 103, 

 pp. 61-79. 

 Graeowski, C. T., and Dethier, V. G. 



1954. The structure of the tarsal chemoreceptors of the blow fly, Phormia 

 regina Meigen. Journ. Morph., vol. 94, pp. 1-20. 

 Graham-Smith, G. S. 



1930. Further observations on the anatomy and function of the proboscis of 

 the blow fly, Calliphora erythrocephala L. Parasitology, vol. 22, 

 pp. 47-115- 



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