CH. VIII] PHOTO-MICROGRAPHY 211 



FIG. 175. Vertical Camera and special microscope stand for photographing 

 embryos and other small specimens in liquids and for photographing large sections. 

 The camera rests on a low table and the operator can stand on the floor while per- 

 forming all the operations. 



The stage of the microscope is attached to the arm in the place of the tube. 

 This stage has two stories. The specimen is shown on the upper and the back- 

 ground on the lower story. 



In focusing, the coarse and fine adjustment of the special microscope stand are 

 used. The large mirror is to illuminate embryo chicks mounted entire, and other 

 large transparent preparations. Trans. Amer. Micr. 1901. 



340. Prints. If the photographic prints are to be used solely for outlines, 

 the well-known blue prints so much used in engineering and architecture may be 

 made. If, however, light and shade and fine details are to be brought out with 

 great distinctness, either an aristotype, platinotype or a bromide print is preferable. 



341. Recording, Storing and Labeling Negatives. In or- 

 der to get the greatest benefit from past experience it is necessary to 

 make the results available by means of a careful record. For this pur- 

 pose the table ( 360) has been prepared. If one gives the information 

 called for in this table, whether the result is successful or not, one can 

 after a time work with great exactness, for the elements of success and 

 failure will stand out clearly in the table. 



342. Labeling the Negatives. After the negative is dry the 

 labeling can be done on the gelatin side with carbon ink. Enough 

 data should be given to enable the certain identification of the negative 

 at any future time. 



343- Storing Negatives. This is satisfactorily done by put- 

 ting each into an envelope and writing a duplicate label on the upper 

 edge, and then the negatives may be placed in drawers in alphabetical 

 order as are the catalog cards of books in a library. One can then find 

 any negative with the same facility that the title of a book can be 

 found in a card catalog. 



PHOTOGRAPHING EMBRYOS 



For photographing embryos and many other small specimens it is 

 more convenient to use a smaller apparatus than the vertical camera 

 just described. It is necessary also to have a more delicate method of 

 focusing. 



344. Camera for Embryos. This is a vertical camera for 

 photographing with the microscope, with the photographic objective in 

 the end of the camera as for an ordinary camera. This is readily ac- 

 complished by having a society screw adapter, and also adapters for 

 the micro-planars or oiher objectives which one desires t6 use. The 



