No. 630] SHORTER ARTICLES AND DISCUSSION 87 



dilute solutions yellow. The lipoclirome is present in the coelomic 

 fluids of the male Chiton, though in very small amount, and, as 

 previously stated, is present in the stroma of the testis. In the 

 female Chiton large quantities are present, in "solution," in the 

 blood and coelomic fluid, and in the ovary it is clearly associated 

 with the great quantity of fat globules there present ; not all of 

 the fat globules are stained with the red pigment, multitudes of 

 the smaller ones being uncolored by it. 



It seems clear that we have here another case where the de- 

 veloping ovary is associated with "fat metabolism"; the red 

 lipoclirome, accompanying a large volume of fatty materials, is 

 prominently concerned (perhaps by reason of its easy oxida- 

 tion) in the growth of the ovary, and both pigment and ^f at are 

 vastly important for the formation of sperms. The occurrence 

 of the ovarian pigment in much higher concentration in the 

 blood and juices of maturing females is comparable to the con- 

 dition found by Steche 5 in certain moths, whereof the blood of 

 the female was chemically differentiated in an obvious way from 

 that of the male. 



That the pigment is concerned in the metabolism of the ovary 

 is shown by the fact that as the ovary becomes mature, but be- 

 fore it is fully so (i. e., early in May), it becomes of a deep green 

 color with imbedded streaks of maroon-red. In surface view the 

 ovary is then green, like that of most chitons, but the salmon or 

 deep orange coloration of the foot, muscle, blood, etc., does not 

 change. Hence, if these animals were to be examined in summer, 

 with the ovary nearly or quite mature, the causal connection 

 between ovarian pigmentation and body pigmentation would 

 hardly suggest itself immediately. It is easily shown, by ex- 

 tracting the pigment in acetone, that the green hue must be due 

 to a relatively simple modification of the original red substance. 

 Such extracts are orange-yellow, are decolorized by HN0 3 , and 

 give a green flocculent precipitate with alkalies. The ovarian 

 eggs themselves, at first colorless, are found by the middle of 

 May to have assumed a faint pink tinge, whereas toward the end 

 of June they become deep green. 



4. Regarding the accidental character of the reddish color in 

 the tissues of adult female chitons, it is sufficient to point out 

 that the foot, where this character is most conspicuous, remains 

 throughout life firmly adherent to the substratum ; the gdls also 



