266 BOLL, ON THE STRUCTURE OF 



weak, shining, and finely granulated contents. In the inside 

 of the covering it appears finely granulated, pale, or in some 

 places striped with peculiarly fine longitudinal markings. 

 If, however, it should have burst, as may be the case by 

 a careless placing of the covering-glass, it forms peculiar 

 dark balls and shapes, which are to be distinguished from 

 the characteristic pipe-like forms of the nerve-tubes through 

 their more finely granulated character, and therefore more 

 clouded appearance, as well as through the want of double 

 outline. 



It is well known that Pflueger saw that in the salivary 

 glands the nerve-fibres approached the alveolus, entered 

 the same, branched out between the single cells, and at last 

 came into connection Avith the epithelium. I can only 

 endorse these statements of Pflueger. Some of my figures are 

 taken from the lachrymal glands of the sheep. In some, 

 exactly as in the plates of Pflueger (taf i, 1 — 4), are to be 

 seen the fibres, already known, which come from the stem of 

 the lachrymal nerve, and enter the blunt end of the alveolus, 

 where they pass into an obscure mass, which is not clearly 

 separated from the neighbouring epithelium. Whilst some 

 of these fibres do not show any further diflference, and are, 

 therefore, not to be separated from the common fibres of 

 Remak, as M. Schultze has pictured them from the spleen- 

 nerves of the ox, there are others which have the peculiar 

 property of containing, buried in their inside, two and 

 even four peculiar, shiny, soft fibres, which are certainly to 

 be considered as axis-cylinders. Cases such as Pflueger 

 pictures in table i, figs. 5 — 9, are comparatively seldom seen 

 in the lachrymal glands of the sheej) and calf. Nevertheless, 

 I have twice undoubtedly observed the entrance of a large 

 medullary nerve into the alveolus, and have been able to con- 

 vince myself of the frequent appearance of these forms in the 

 submaxillaries of the rabbit, which certainly, of all glands, is 

 the be*it for the study of nerve-endings. Oftener, however, 

 forms are to be seen in the lachrymal glands of the sheep, as 

 in fig. 3, where an undoubted fine medullary nerve enters 

 the alveolus, and branches off amongst the epithelial cells. 

 To follow the continuation of the axis-cylinder, which is 

 enclosed in the fibres of Remak, through the finely granii- 

 lated mass of the place of entrance, is very difficult, although 

 some of my preparations show undoubtedly a soft fibre which 

 branches out amongst the epithelial cells, but whose connec- 

 tion with the axis-cylinder at the place of entrance is not 

 proved with certainty. 



Lastly, I must shortly mention the peculiar organs which 



