264 BOLL, ON THE STRUCTURE OF 



rise to clifFerences. Thus, for instance, in the glands of 

 the calf the cells have large dimensions, and a distinct, 

 richly developed cell-substance. The projections become 

 prominent by gradual contraction of the cell-body, and 

 branch very numerously, generally at a very acute angle. 

 The cells of the rabbit and dog are very thin and small ; 

 the processes, which project sharply from the cell-body, 

 branch much less. Between these two forms stand the 

 isolated cells of the lachrymal glands of the sheep. 



If, now, we trace these interesting cells by means of 

 the above method (best in the lachrymal glands of the calf) , 

 we soon find that they do not present then\selves alone, 

 but form singular nets, with tree-like branched tendrils and 

 complicated anastomoses ; it may even so happen that we obtain 

 one of these networks which still retains the form of the 

 alveolus, like a basket in which the acinus of the gland lies. 

 The epithelial cells adhere to the spaces in the net which 

 open from the periphery into the hollow enclosed by the net- 

 work, as by a "scaffolding" (fig. 1). By the inner connec- 

 tion of the surrounding cell-basket with the secreting cells 

 of the alveolus, it often seems as though two kinds of cells 

 were in direct connection. On the other hand the branched 

 cells of the first can easily be mistaken for those of the 

 alveolus — for instance, in such a case as Avhere one or more 

 of the processes are knocked ofi". • 



The radiate and much branched tendrils of the cells are, 

 as already shown, smooth and band-like. In the rabbit and 

 sheep the cells themselves are so. In the glands of the calf, 

 and particularly in those of the dog, the parts of the net 

 where the nuclei lie, that is, the cell-bodies, show a distinct 

 thickening. Here we have, according to my idea, a perfectly 

 undeniable exj)lanation of the peculiar formations, which some 

 time ago were described and figured by Giannuzzi from the 

 submaxillaries of the dog, as " mondchen " (lunula). The 

 crescent-shaped forms (fig. 2) are to be obtained in numbers 

 from the lachrymal glands of the calf by means of maceration. 

 They are multipolar cells, which have retained the curve of 

 the alveolus, and are seen in profile, their processes lying in 

 the plane of the profile. If one allows such a form to roll 

 about under the microscope, the transformation of the peculiar 

 crescent form into a multipolar cell takes place under one's 

 eyes. Fig. 2 shows two forms, which appear not unfre- 

 quently, where one or more processes are disposed about the 

 crescent, and, coming out of the profile-plane, become visible. 

 If this explanation is adopted the want of the lunula? in the 

 submaxillaries of the rabbit, where both Pfiuegcr and Kollikcr 



