REIGHARD ON PHOTOGRAPHING VERTEBRATE EMBRYOS. Ill 



On May 15, 1807, Professor Wheeler called the attention of the writer 

 to the damage being done to water-lily pads in the wild-garden. The pads 

 of both NupJtar advcna and of Nymphea odarata were furrowed by some 

 miner. The pads had been badly eaten in some places and many con- 

 tained living larvae and pupae. A quantity were collected and placed in 

 cages; after two or three days the adults emerged. The following is 

 taken from notes made at the time. 



The insect works by tunneling or plowing a furrow which extends 

 from the top of the leaf to the lower epidermis. This tunnel is often 

 several inches in length and winds about in all directions in a serpentine 

 manner. At the end of the tunnel in which the insect is feeding is a 

 tube made of fresh green parenchyma from the leaf, this is chewed up 

 fine and bound together with silk. From the front end of this tube the 

 insect extends its head and feeds; the tube is fast in the furrow and is 

 not drawn along like a true case as was suspected. 



The pupae are partially active and lie in the tubes with the head 

 toward the front. They are light apple-green in color as are the larvae, 

 but both have wine-colored spots or patches of irregular form and in- 

 definite in position in the different specimens. 



After two or three days from the time the pads were placed in the 

 cages the adults commenced to emerge. They belong to the genus Cheir- 

 onomus and are probably a new species. The color is uniform light apple 

 green. 



On August 1 a second brood was seen at Pine Lake, Ingham county. 



APPARATUS FOR PHOTOGRAPHING VERTEBRATE EMBRYOS. 



BY JACOB REIGHARD, ANN ARBOR. 



The purpose of the apparatus is to secure the greatest possible depth 

 of focus with a magnification of ten to twenty diameters. For this pur- 

 pose a low power lens (80mm. Leitz) is used on a long vertical camera. 



The large photomicrographic camera of Zeiss, which may be extended to 

 about five feet, is attached to the wall in a vertical position. The micro- 

 scope is clamped to a bed plate which is provided with levelling screws, 

 so that the optical axis of the microscope may be made coincident with 

 that of the camera. 



Attached to the wall alongside the camera is a vertical metal rod which 

 bears at intervals large milled heads by means of which it may be rotated. 

 The lower end of the rod is connected by means of a bevel gear and two 

 Hookes' keys, to a pair of grooved brass wheels which are supported 

 by a pillar that rises from the bed plate. From these wheels cords pass 

 over the coarse adjustment screws of the microscope. The cords may 

 be tightened by adjusting the grooved wheels along a horizontal rod. 

 By this arrangement it is possible to focus with the coarse adjustment, 

 with the camera bellows fully extended. 



The embryos (Amia) are attached by collodion to discs of cardboard 

 and photographed by light focused upon them nearly horizontally from 

 a 90 degree arc lamp. 



