Journal of Applied Microscopy. 



107 



The Glandular Stomach of Birds. 



In his "Comparative Anatomy and 

 Physiology of Vertebrates," vol. 2, page 

 161, Prof. Owen says of this organ: 



"In the majority of birds the gastric 

 follicles are simple, having no internal 

 cells, dilated fundus, or contracted neck; 

 but from their blind extremity proceed 

 with a uniform diameter to their inter- 

 nal orifice. This form obtains in the 

 zoophagus and omnivorous birds. In the 

 dove tribe the follicles are of a conical 

 shape; in the goose and turkey they 

 present internal loculi; in the ostrich 

 and rhea these loculi are so developed 

 that each gland forms a racemose 

 group of follicles, terminating in a com- 

 mon aperture in the proventriculus." 



Fig. 1. 



I had supposed until a little more than 

 a year ago that the above statements 

 were correct. At that time I had set some 

 students to sectioning for the microscope 

 the glandular stomach of a meadow lark. 

 When ready they called on me for an 

 explanation of the structure that was so 

 different from what they had been ex- 

 pecting to find. Fig. 1, taken from one 

 of the slides made at that time, will 

 show fairly well what was seen at that 

 time under low power. 



To explain the figure a little in detail, 

 the outside consists of the usual three 

 coats: serous, muscular, and submu- 

 cous, not differentiated in the figure. In- 

 side the submucous are a series of 

 plumose glands, each consisting of a 

 series of tubuli, or rather acinic, for in- 

 stead of being simple tubes, 'each tube 

 has a lining of short columnar cells with 



a nucleus near the center, like the gas- 

 tric tubules in the human stomach. 

 These lie at different angles to a com- 

 mon duct in the center of the plume, 

 this duct opening into the interior of 

 the organ. This is contrary to the first 



"1^x^00 



two of Prof. Owen's statements: "Simple 

 and having no internal cells." Figure 2 

 shows a camera lucida drawing of 

 seven cells in a tubule from the gland- 

 ular stomach of a sparrow hawk, where 

 they were slightly separated, magnified 

 300 diameters. The cells are bounded on 

 the basal side here by the connective 

 tissue forming the framework of the 

 whole gland. 



^'9 J > 300 



Figure 3 gives a cross section of one 

 of the tubules in the plumose gland from 

 the same bird, the sparrow hawk, also 

 a camera lucida drawing. The spurs 

 around the sides of the acinus are where 

 the wall of this is joined by walls of ad- 

 joining acini. 



Inside the plumose glands are a set of 

 short tubular glands, varying some in 

 length, but usually not more than a 

 fourth the length of the i^acemose 

 glands, each tube an independent gland 

 which opens direct into the interior of 

 the organ. These glands were lined with 

 cells, or rather are a layer of cells lining 

 the tube, the wall of the tube being con- 

 nective tissue of the same kind as the 

 walls of the acini of the plumose glands, 

 but the cells are somewhat different. 



This is shown in Fig. 4, where the outer 

 or blind end of one of the tubular glands 

 is shown. These cells are more elongated 



