THE CONTROL OF CEMENT GLAND DEVELOPMENT IN THE CRAYFISH, CAMBARUS

Abstract

1. The morphology and sequence of events in the course of normal development of the cement glands of female crayfish of the genus Cambarus are described and a technique for the study of the developmental rate of these glands is outlined.2. In mature female crayfish, removal of the eyestalks produces an acceleration in the rate of development of the cement glands. Experimental evidence suggests that a further increment in rate may result when cerebral ganglia and circumesophageal connectives from mature females of the same species are implanted in the ventral haemocoel of destalked, mature animals.3. Both destalking, and destalking with subsequent implanting of nervous tissue from immature female donors, lead to a cessation of cement gland development or fail to initiate development in immature animals.4. The cement glands of mature females subjected to 20 hours of illumination per day appear to develop more rapidly than those of comparable animals maintained in constant darkness. However, modification of day-length is not sufficient to initiate cement gland development in quiescent immature females.5. A correlation between developmental state of the cement glands and degree of oö development is presented.6. Characteristics of a possible humonal control of the cement glands are discussed as well as the contribution of this information to the more general subject of humoral control of secondary sexual characteristics in the decapods.