332 Effa Fmik Mulise. 



cells. Such a gland is a differentiated part of the epidermis. As the 

 acinus of a gland enlarges, it pushes farther and farther away from 

 the epidermis into the cutis, with the elements of which it has no 

 direct connection. The strata of the cutis increase in depth and are 

 rearjanged and adapted to the bodies of the glands. These epidermal 

 glands go by the name of cutaneous glands to distinguish them from 

 the one-celled glands of the epidermis, the beaker cells. 



The present investigation has convinced the writer that there 

 exists in the cutis of the toad only one kind of gland. All cutaneous 

 glands, however different they may appear, are developmental stages 

 of the one kind. The climax of the complex, graduated series is 

 reached by the large sacs that hold in readiness a great quantity 

 of granular secretion. Those Batrachians in which the parotids 

 occur present the greatest differences in the size and structure of 

 the glands, and in the location of their sacs in the cutis. 



Literature. Many authors, whether considering the glands of Ba- 

 Trachians from a histological, embryological or physiological point 

 of view, have proceeded on the theory that at least two kinds exist. 

 The conclusions of those who have discussed the question of the 

 number of kinds of glands differ,. The majority believe that two, 

 even three, or four kinds of glands are present. Many of the earlier 

 writers made their classification largely on the basis of size into 

 large and small glands, or according to the shape of the gland acinus. 

 (Ascherson, '40, Eckhard, '49, Rainey, '55, Hcnsche, '56, Szczesuy, 

 '07, Ciaccio, '67, Leydig, '67.) The more recent classification is 

 into mucus and poison, nuclear, or granular glands, based on a dif- 

 ference in the epithelial structure and in the secretion produced. 

 (Englemann, '70, Schultz, '89, Seeck, '91, Drasch, '92, Weiss, '99, 

 Phisalix, '00, Esterly, '03, Bristol and Bartelmez, '08.) Esterly 

 speaks of the large poison glands and of the mucus variety. He finds 

 that in every large gland there is the fundament of a new gland, 

 which resembles glands of the mucus variety. He, however, shows 

 no relation between the separate mucus glands and the large poison 

 glands. Several investigators (Calmels, '83, Leydig, '92, Vollmer, 

 '93, Nicoglu, '93, Junius, '96, Ancel, '01) have given evidence or 

 expressed their belief in one kind of cutaneous gland. 



