204 CALIFORNIA FISH AND GAME 



and in the southern black-tailed deer of the Pacific Coast, the meta- 

 tarsal gland is of medium length, being, in average adults, about three 

 inches in length in females, and three and one-quarter inches in length 

 in males. In the black-tailed deer, although the longtli of the metatarsal 

 gland is three times that of the same organ in the white-tailed deer, 

 the width of the metatarsal gland is actually less, rarely being as much 

 as one-half inch. In the mule deer, the metatarsal gland reaches its 

 highest development, attaining a length of as much as five and one-half 

 inches. A large four-point buck I measured at Hackamore Reservoir, 

 eight miles north of Happy Camp, Modoc County, California, on Sep- 

 tember 24, 1924, had a metatarsal gland of five and one-half inches in 

 length. In an adult Rocky Mountain mule deer doe of average size 

 measured at the same time and place, the metatarsal gland had a length 

 of four and one-half inches. A male fawn of the Rocky Mountain mule 

 deer, approximately four months old, measured at the same locality and 

 on the same date, had a metatarsal gland three inches long. It will thus 

 be seen that a four-months-old mule deer fawn may have a metatarsal 

 gland as long and as wide as that of an adult black-tailed deer. 



Form and size of antlers of the mule deer and the black-tailed 

 deer may vary greatly. The form, size, and color of the tail in the two 

 species is fairly constant, but I have found the lengtli of the metatarsal 

 gland to be subject to the least variation, and therefore I regard it as 

 the most conservative and the most reliable single external character 

 that can be used to differentiate between the two species. Wliere 

 liybrids of the Columbian black-tailed deer and the mule deer occur, I 

 have found that the size of the metatarsal gland is intermediate between 

 that of the two species. However, in adults of either species I have 

 found that there is no overlapping except where actual interbreeding 

 fiJid hybridization has taken place. 



EYE SHINE 



In former times, before the practice became unlawful, many deer 

 were killed by "jack hunting" at night. The method used was for the 

 hunter to carry a small, powerful acetylene searchlight attached to his 

 hat or cap. When such a light is carried in this manner, close to the 

 eyes of the hunter, the light from the lamp is reflected back from the eye 

 of the deer to the eye of the hunter. This "eye shine" is particularly 

 observable in nocturnal animals such as owls, poorwills, deer and other 

 night prowlers. 



Light reflected from the eyes of nocturnal animals under such cir- 

 cumstances has been found to vary in color, and certain types or kinds of 

 animals have been found to have a characteristically colored "eye 

 shine." In order to determine the facts in the case and to settle various 

 arguments, I made especial effort to examine and to record the color 

 and other details of the "eye shine" in mule deer. On December 14, 

 1929, on the floor of Yosemite Valley, at 8.80 o'clock, I watched two 

 bucks with considerable interest as they "horned" a certain slender, 

 smooth willow sapling. They were so intent on this operation that I 

 was able to watch them at a distance of twenty feet for several minutes 

 by the aid of a powerful electric flashlight. I found that under such 

 conditions their eyes shone like two bright-colored flames of white fire. 

 At certain times when the bucks turned their heads and were not 



