314 Journal of Applied Microscopy. 



These older views maintained that the chief cells of the peptic glands were 

 similar to the chief cells of the pyloric glands, the only difference in the two 

 kinds of glands being the absence of parietal cells from the pyloric glands. 

 After a careful historical review of the subject which shows that differences in 

 the cells from different parts of the fundus glands had already been noted, the 

 author gives the results of his studies on the rabbit, dog, and cat, especially the 

 last two animals. 



The method employed was to cut off bits of gastric mucosa with scissors 

 directly into Foa's blood-fixing fluid (equal parts of mercuric chloride in 95 per 

 cent, alcohol and a 2-4 per cent, aqueous solution of potassium bichro- 

 mate), leaving them there from one-half to two hours, according to size. Then 

 they were washed in 70 per cent, alcohol for twenty-four hours, or until all the 

 bichromate was removed. They are then put into 95 per cent, alcohol and 

 imbedded in paraffin by the oil of bergamot method. Control specimens were 

 carried through in alcohol, aqueous bichromate mixtures, and Hermann & 

 vom Rath's osmic mixtures. The Foa mixture was found to fix the granules 

 perfectly. 



Biondi tricolor stain, Mayer's hemalum, Erlich's acid ha^matoxylin, and 

 many other special stains were used, among them stains to show the presence of 

 iron compounds in the cell. 



The author concludes that in the cat and dog the fundus or peptic glands contain 

 two kinds of chief cells, those of the body and those of the neck of the gland. The 

 former secrete ferment, as shown by the presence of zymogen granules near the 

 lumen. There is also in the outer part of the cell a deeply staining substance 

 of the nature of chromatin, which stands in a genetic relation to zymogen and 

 is known as prezymogen. The neck cells are considered to be the same as the 

 pyloric gland cells in the cat and dog because neither kind of cells contains 

 zymogen granules and only traces of prezymogen. Both groups secrete a 

 substance reacting similarly to certain stains that may be called mucin. Mucin 

 cells have been also found in the fundus glands of the mink, rabbit, mouse, rat, 

 squirrel, ground hog, chipmunk, pig, and sheep. The further relations of the 

 glands will be discussed in another paper. a. m. c. 



For convenience the author describes 

 Morgan, T. H. Experimental Studies of the . ^ i ^i j- n • i i 



Regeneration of Planaria maculata. Archiv. experiments under the foUowmg head- 

 f. Entwick. der Organismus. 7: pp. 364- ings : (1) Regeneration of cross-pieces 



397, 41 figs, in text, 1898. , . .. r ..1 u 1 /in 



•^-"'^ >= ■ ' -' from various parts of the body. (2) 



Regeneration of short pieces from the side. (3) Regeneration of small pieces 

 from the posterior end. (4) Regeneration of long pieces from the side. (5) 

 Regeneration of triangular pieces. (G) Regeneration of very short cross-pieces. 

 (7) Regeneration of a head at the posterior end of a cross-piece. (8) Transfor- 

 mation of an old piece into a new worm. 



Material was collected in the vicinity of Wood's Holl, Mass., and the 

 experiments continued from June during the following winter. The largest of the 

 worms used measured about 20 mm. in length and one-half mm. in breadth. Most 

 careful experiments were carried out, and the following gives in part a summary 

 3f his results. Cross-pieces of the body develop a new head and a new tail, the 



