Roest j w van der (2 risultati)

Egg laying activity of the pond snail Lymnaea stagnalis changes with age. Initially there is an increase of egg laying activity. At an age of about 250 days egg laying activity starts to decrease and eventually ceases. Lymnaea thus has a clear post-reproductive period during its life cycle. In order to locate mechanisms which are responsible for the cessation of egg laying activity electrophysiological, behavioural and injection experiments were done and the morphology of the neurons controlling egg laying activity (the caudodorsal cells, CDCs) were studied. On the basis of the results of the foregoing experiments and observations it is hypothesized that due to degeneration of particular CDCs in old animals, input to the egg laying control system is terminated resulting in cessation of egg laying. 9 pp., 4 figs, gr. 8.…

Condizione: very good. [s.l. : s.n.], [1946]. Paperback. 38 pp. 32 cm. Gestencild. Eenzijdig bedrukt. Proefschrift Vrije Universiteit Amsterdam. Omslag gebruind. Condition : very good copy. Keywords : RECHT, Nederlands recht staats- & bestuursrecht.