262 BOLL, ON THE STRUCTURE OF 



valve a smaller number of strice may be counted. Although 

 my opinion may not agree with that of any one of the most 

 distinguished microscopists, I am at present inclined to the 

 belief that the Diatomacece, like any other organism which 

 is produced from a germ, is born of small size, and grows as 

 it passes through the various stages of life. And I believe 

 that this growth may take place in various ways in different 

 species. But as an inquiry of this kind is ultimately con- 

 nected with the very thorny question of the true limits 

 between the genera, species, and varieties of the Diatomacese, 

 I will reserve it for a future occasion. 



On the Structure of the Lachrymal Glands. 

 By Franz Boll. 



Recently, in histological researches, peculiar star-shaped 

 cells have been noticed in the aciniferous glands. Krause 

 was the first man who isolated these, in the case of the 

 parotid of a cat, by means of maceration in vinegar. He is 

 inclined to treat them as nervous organs. Henle also 

 describes stellate cells in the walls of the rennet glands, as 

 well as the parotid and mammae. He also thinks that they are 

 most likely of a nervous character, although he has never 

 seen any connection with the nerve-fibres. Pflueger describes 

 multipolar cells in the salivary glands of the rabbit. He 

 holds them to be multipolar ganglion-cells, and observed on 

 one side their connection with the fibres, and on the other 

 side with the secretory einthelial cells. Finally, Kolliker 

 has made closer researches concerning the cells in question 

 in the salivary glands. He considers them to be simply 

 forms of the covering structure of the alveolus, which seem 

 to him to represent a kind of reticulum. 



I began to give my attention to these doubtful objects 

 whilst examining the lachrymal glands in the summer vaca- 

 tion of 1867, and continued in Bonn later on to do so. 



The lachrymal glands of the pig, sheep, calf, and dog, also 

 the submaxillary of the rabbit, calf, and dog, and the parotid 

 of the cat and rabbit, served me as objects of examination. 

 The following arc the methods of isolating these cells : — 

 Maceration in vinegar (Krause); treatment with bichro- 

 mate of potash (Ilonle) ; with 33 per cent, liquor potassse 

 (Pflueger); and placing in a solution of iodine, later on 



