128 KINETIC HORMONES — II 



4.12 OVIDUCAL GLANDS 



Gastropoda. Increased formation of secretory material in the 

 albumen gland in the reproductive ducts of the slugs, Arion and 

 LimaXy has been shown to depend on a hormone from the gonad 

 (Laviolette, 1956). The growth of the glands is also stimulated 

 and it seems probable that the hormone is having a morphogenetic 

 effect rather than the strictly kinetic action of releasing the 

 secretion into the ducts. 



Amphibia. The oviducts of Anura and Urodela secrete jelly, 

 which is laid down round the ovum and swells when it is laid in 

 water. At first it serves a protective function, but may be eaten 

 later by the newly-hatched young. In Bufo arenarum it has been 

 shown (Smith, 1955) that injection of a variety of hormones can 

 induce the secretion of this jelly from the oviducal glands. The 

 most consistent results seem to be obtained with progesterone- 

 like substances from the simple corpora lutea that form during 

 ovulation in the ovary (Galli-Mainini, 1951), under the morpho- 

 genetic influence of the luteinizing hormone, LH, from the 

 adenohypophysis (§ 2.123; Table 15). 



This secretion of jelly has also been induced by prolactin, 

 when supplied from implanted toad hypophyses ; but this hormone 

 has not been confirmed as physiologically active in nature. It is 

 probably the same as luteotrophin, LSH, the action of which in 

 mammals would be to stimulate the secretion of progesterone. If 

 it is the same in Biifo, this would be one of the rare cases in which 

 the secretion of a hormone with a kinetic action is subject to 

 endocrinokinetic stimulation (§ 4.2) ; but the main function of 

 progesterone is morphogenetic and this kinetic action seems to be 

 subsidiary. It is claimed however that prolactin can act in the 

 absence of the ovary (Houssay in Nalbandov, 1959). 



Ayes. The single oviduct of young birds secretes albumen most 

 freely in response to stimulation by progesterone in the presence 

 of oestrogen; in mature birds the process is facilitated by the 

 presence of the egg yolk, though this may be replaced by any 

 smooth foreign object such as a glass bead of suitable size (Nal- 

 bandov, 1959). 



Mammalia. The uterus is a derivative of the oviduct, in which 



