An Experimental Study on the Relationships between Limb and Spinal Cord in the Embryo of Eleutherodactylus martinicensis

Much has been written on the experimental study of development in the vertebrate nervous system. The effect on the centre of extirpation and transplantation of organs in the peripheral field have been extensively studied, but the number of species which have been employed for these researches is small. The vast majority of such experiments have been on the Urodele Amblystoma (Detwiler, 1936; Piatt, 1948); others have used either the chick (Bueker, 1943; Hamburger & Keefe, 1944) or various species of Anura (May, 1930; Taylor, 1944). The effect of organ extirpation in the mammalian foetus has also been investigated (Barron, 1945; Hess, 1957). Although much has been learnt about the dependance of central neurones on peripheral connexions, the conditions necessary for function in transplanted limbs and muscles (Weiss, 1936), and recently on chemical stimulation of the growth of nerves (Levi-Montalcini, 1958), there are still fundamental problems for which at present only theoretical explanations are available.