304 



SCIENCE. 



[N. S. Vol. XII. No. 295. 



The Structure oj the Poison Glands of Sehilbeo- 



des gyrinus : By Hugh Daniel Reed, 



Cornell University. 



The poison gland is supposed to be in the 

 axil of the pectoral fins. It is in reality just 

 beneath the epidermis and almost entirely 

 surrounds the spine. Both dorsal and pec- 

 toral spines have poison glands. The gland 

 tissue is composed of large, coarsely-gran- 

 ular, doubly-nucleated cells. Each poison 

 cell is surrounded by a layer of spindle- 

 shaped epithelial cells. The clavate cells 

 of the skin are identical in structure with 

 the poison cells. They are wanting in 

 those places which are entirely covered or 

 protected by other organs. From their re- 

 semblance in structure to the poison cells 

 and their distribution, it is probable that 

 their function is one of protection. The 

 poison cells are regenerated from the cells 

 of the epidermis. 



Before the poison can be efi'ectual the 

 cell membranes must be destroyed, for 

 there is no duct leading from the gland to 

 the exterior. The spine is entirely covered 

 by epidermis which has to be punctured. 



Development and Relations between the Intesti- 

 nal Folds and Villi of Vertebrates : By W. 

 A. Hilton, Cornell University. 

 Folds, villi and valvolae conniventes are 

 convolutions of the mucosa alone, other 

 foldings involving the muscular coats not 

 being considered. Folds and villi are 

 homologous, villi being more specialized 

 and occurring usually in otherwise highly 

 specialized vertebrates. Several influences 

 upon size and form of villi are easily recog- 

 nized, such as the influence of food and 

 size of the animal. By phylogenetic and 

 ontogenetic study of a number of species it 

 is found that there are at least two ways in 

 which the villi are formed from folds. The 

 more usual way being like that which takes 

 place with the chick, that is, straight folds 

 becoming more and more wavy until very 



zigzag folds are produced and villi formed 

 from these by separations which take place 

 at the tip of the fold angles downward. 



Villi are present in the large intestines of 

 most mammals sometime before birth, and 

 occur also in the appendix vermiformis of 

 man before birth, possibly showing the ap- 

 pendix of man to be an atrophied part of 

 the ccecum. 



Hystolysis of Muscle in the transforming Toad 



{Bufo lentiginosus) : By Louise Katz, 



Ithaca, K". Y. 



It is shown in this paper that while the 

 outward changes in transformation are ex- 

 ceedingly rapid, taking place in about three 

 days, the internal changes are in process 

 for a considerably longer period. The first 

 sign of muscle change is a myotome near 

 the base of the tail opposite the grow- 

 ing legs. Here a few fibers, often but a 

 single one, occur on each side. Later, 

 when the legs are about three-quarters 

 grown, degenerating fibers are scattered all 

 along the tail, but are most numerous at 

 the tip. 



Forms of degeneration ; there are four 

 quite well-marked types : 



1. Mass degeneration, in which the whole 

 fiber degenerates in one or more large 

 masses. 



2. Degeneration with transverse bands of 

 degenerating substance, alternating with 

 bands of normal muscle. 



3. Breaking of the fibrillse into smaller 

 fragments, the so-called sarcolytes. 



4. Transformation into transverse bands 

 with intermediate gaps as if liquefaction 

 had taken place. 



In all the types the changes appear to be 

 intrinsic in the muscle itself; homogeneous 

 material is produced, reacting characteris- 

 tically with the various stains and fixers, 

 and disappearing by liquifaction in situ. 

 Thus far I have found no evidence of frag- 

 mentation of the nuclei, nor marked in- 



