114 



SCIENCE. 



[N. S. Vol. III. No. 56. 



of specimens were exhibited. Tlie general 

 summary of the forms thus far studied may 

 be made as follows : 



Mammals possess an area as a rule; in 

 some, however, notably the dog, no area 

 can be distinguished. The primates are the 

 only class in which a fovea is present. 



All birds examined, except the chicken, 

 have one or two well-defined foveas with 

 areas of various forms. In the domestic 

 chicken no trace of fovea or area has been 

 observed. Both the quail and partridge 

 have well-developed foveas. Among the 

 birds studied, the following have a central 

 fovea with circular area: turkey, duck, par- 

 tridge, quail, pigeon, song and English 

 sparrow, kinglet, robin, bluebird, and crow. 

 The goose and ring-neck plover possess a 

 central fovea and a band-like area. In the 

 tern we find two foveas and a band-like area 

 extending horizontally across the retina. 

 One of the foveas, corresponding in posi- 

 tion to the human fovea (nasal) is situated 

 near the optical axis and within the area. 

 The other fovea (temoral) is located above 

 the band-like area and close to the ora ser- 

 rata. Its position would indicate that it 

 serves for binocular vision. Both the spar- 

 row hawk and the red-tailed buzzard hawk 

 possess two foveas, each one surrounded by 

 a well-defined circular area and connected 

 by a slightly developed band-like area. The 

 fovese in the hawks are much closer to- 

 gether than in the tern and are both com- 

 paratively near the optical axis, the tem- 

 poral fovea apparently moving towards the 

 center of the eye as the position of the eye 

 in the socket changes from the lateral to the 

 frontal type. The kingfisher resembles the 

 hawks in the above particulars. 



As to the reptiles, amphibia and fishes, 

 the turtle and frog have band-like areas ex- 

 tending across the eye horizontally just 

 above the nerve. These are not marked by 

 any thickening of the retina, but by a closer 

 packing together of the cells, especially well 



seen in the ganglion cell layer. In none of 

 the fishes examined has either area or fovea 

 been found. The retina is, however, much 

 thickened over the superior half. 



10. G. C. HuBEE : Tlie ending of the chorda 

 tympani in the sublingual and the suhmaxillary 

 glands (ivith demonstrations'). 

 The observations reported were made on 

 preparations obtained from young dogs and 

 puppies ; the tissues were stained with the 

 double Golgi-Cajal method and the Ehrlich- 

 Bethe methylene blue method. The follow- 

 ing conclusions were reached : 



1. The cells of the sublingual and the 

 submaxillary ganglia are multipolar in type; 

 they belong to the sympathetic system; this 

 is shown in preparations impregnated with 

 chrome silver. 



2. The axis cylinders of the sympathetic 

 cells follow the larger and smaller gland 

 ducts and form a plexus about the intra- 

 lobular ducts. From this plexus fibres are 

 given oif that form a second plexus about 

 the alveoli outside of the membrana propria. 

 From this second plexus ultimate fibrillfe 

 pass off, penetrate the membrana propria and 

 end on the gland cells. 



3. The chorda tympani consists of fibres, 

 some of which end in the form of a pericel- 

 lular end-basket arouad the cells of the sub- 

 lingual ganglion, while others have no con- 

 nection with this ganglion, but end in a 

 similar manner in the submaxillary ganglion. 

 ]S"o fibers of the chorda tympani end on the 

 gland cells. 



4. The sympathetic fibres following the 

 branches of the submaxillary artery are 

 axis cylinder branches of the sympathetic 

 cells in the superior cervical ganglion. As 

 far as has been determined, they end on the 

 blood vessels. 



11. Gr. W. FiTz : A working model of the 



eye. 



Dr. Fitz showed a working model of the 

 eye consisting of a skeleton eye set in gym- 



