AbstractsAstronomy & Space Science

[...]I thought it possible that a study of the secretory and motor functions of the stomach of the lower vertebrates might reveal importantinformation about the phylogenetic history of the mammalian stomach. I undertook this investigation of gastric secretion and motility in the lessorganized vertebrates in the belief that it would lead to an approach of a better understanding of the complicated secretory and motor processesof the stomach of the more highly organized mammals.The following vertebrate animals were employed: Elasmobranch fishes (skate), Amphibia (Necturus or mud-puppy, andfrog), and birds (pigeon and chicken). Early in the research many differences in gastric physiology between these lower vertebrates and the mammalswere found. With the view of determining whether the gastric processes of the lower forms were recapitulated in the ontogeny of the mammal, I usedthe stomach of the mammalian foetus and new-born (cat and dog). Finally, since the lower vertebrates (except birds) were cold-blooded animals, Idecided to investigate a mammal that has a low body temperature. For this purpose I chose the groundhog during hibernation.