1908] Infant Cannibalism among Animals. 127 



mollusks has this curious fact of paedophagy long been known 

 it has been noticed among the Crustacea. Thus in Daphnia, 

 the dehcate water-flea, wliile the eggs are still in the tubular 

 ovary, the ovigerous cell may divide into four, one of which 

 becomes an ovum and increases in size by devouring the other 

 three. In the Phyllopod A pus, the egg when first distinguish- 

 able, is not a single cell, but a group of four cells each with a 

 large nucleus. The nucleus in one assumes a different character, 

 becomes clearer, and more rotund, exhibiting two or more large 

 granules or germinal spots, while the three others show a mass 

 of granules in the nucleus. The.se three nuclei grow rapidly, 

 elaborate food, and feed the fourth cell so that it survives, w'hile 

 they themselves disintegrate. No doubt this strange phe- 

 nomenon of cannibalism, in the earliest stages of development, 

 mav be more widespread than is at present supposed. Botanists 

 have long been familiar with a parallel condition in certain 

 plants. Thus, in the Mistletoe {Viscum album), one seed may 

 contain two or three embryo plants. Some years ago Dr. 

 Beard, of Edinburgh, boldly compared the embryo of the 

 highest Vertebrates to a parasite receiving nutriment by a 

 placental arrangement from its parent. About the same time 

 Professor Mcintosh, of St. Andrews, published an account of 

 the remarkable features of the ovary in Zoarces viviparus, the 

 viviparous blenny, the ovarian walls being complexly folded 

 and richly vascular so that the young fish inside are bathed in a 

 nutritive serum until far advanced in larval life. In making 

 sections of the ovarv, and contained voung, of that species over 

 a quarter of a century ago, I found what appeared to me to be 

 particles of yolk in the alimentary canal which I had difficulty 

 in tracing to the so-called absorption or inclusion of the yolk- 

 sac. Dr. Scharff, of the Royal Museum, Dublin, was at the 

 same time making a study of the early egg in Zoarces and other 

 fishes, and the number of eggs present in the ovary of the 

 viviparous blenny struck me as remarkable if only 12 or 15 young 

 were ultimately produced. Could it be that in some way the 

 non-developing eggs serA-ed as food to nourish the rapidly grow- 

 ing larvae emerging from a limited number of ova ? The question 

 presented itself to me. It appeared possible but hardly probable. 



Dr. Gilchrist, a distingtiished Scottish biologist, and 

 officially in charge of the fisheries of Cape Colony for some years, 

 has shown that such a surmi.se was not far astray. He has 

 proved it to be true in the South African CatcBtyx messieri, 

 Gtinther, a fish 1 to 2 feet long, and occurring apparently at 

 considerable depths ranging from 400 to 700 fathoms. H.M.S. 

 "Challenger," in her famous scientific cruise, secured a male 



