46 SUMMAEY OF CUERENT EESE'AECHES EELATING TO 



colourless, pink, and yellow — the pink and yellow being due to the two 

 lipochrome pigments, tetronerythrin, and lutein. The yellow, as Heira 

 pointed out in 1892, is characteristic of the female when the ovary is 

 approaching maturity. The pink colour appears in individuals, especi- 

 ally in males, which are approaching the period of a moult. 



An estimation of the fat content of the blood, by means of saponifica- 

 tion and extraction of the fatty acids, gives the following average 

 numbers : for colourless blood, 0'059 p.c. ; for pink blood of males, 

 0*086 p.c. ; for yellow blood of females, 0" 198 p.c. Thus the breeding 

 females are shown to possess an excess of fatty material in the blood, 

 and the yellow lipochrome is seen to represent a higher fat value than 

 the pink. 



Besides the blood, the "liver" also exhibits periodic variations in 

 the amount of fat present, fat being sometimes 12 p.c. of the total weight, 

 sometimes as low as 4 p.c. The females maturing their ovary, and having 

 yellow blood, always have a large proportion of fat in the liver. 



Crabs of both sexes infected with Sacculina always show a large supply 

 of fat in the " liver." In the case of Garciiius the blood of infected 

 individuals is either colourless or pale yellow, but in the case of Inachus 

 the blood becomes charged with lipochrome, as the result of infection, 

 though this lipochrome always shows the presence of the pink colom- as 

 well as the yellow. 



The difference in reaction of the blood in the two cases is explained 

 as consistent with the small effect that Sacculina exerts on all the char- 

 acters of Carcinus compared with its effects on Inachus. 



The investigation shows that Sarculina exerts a marked influence on 

 the fat-metabolism of the host, and the results are on the whole consistent 

 with the view that Sacculina influences the host to assume the female 

 characters by acting the same part in fat-metabolism as the ripening 

 ovary does in a normal female. 



Sense of Smell in Coenobita.* — J. Doflein maintains that many 

 aquatic animals have olfactory as well as gustatory organs. Both are 

 chemo-receptive, but in different ways. The evidence of an olfactory 

 sense that Doflein has previously brought forward was based on a study 

 of Decapod Crustacea. He now refers to Borradaile's observations on 

 Ccmobita, which is attracted in the dark to Fandanus-irmts or roasted 

 coco-nut. They hold their antennules above their heads and move them 

 about. It is on these appendages in aquatic forms that the smelling 

 hairs are borne. 



Habits of Thalassina anomala.f — A. S. Pearse has studied this 

 interesting Crustacean, which burrows at the edges of the Philippine 

 estuaries near or above the usual high tide mark. It burrows chiefly 

 with the first pair of legs, but uses the second pair as well in pushing 

 the loosened material out at the mouth of the hole. The burrows go 

 below the water level. It can l)reathe in poorly aerated water, and appa- 

 rently in adaptation to this the branchiostegites are movable on the 

 dorsal portion of the carapace by a sort of flexible hinge-joint. It seems 



• Biol. Centralbl., xxxi. (1911) pp. 706-7. 



t Philippine Journ. Sci., vi. (1911) pp. 218-15 (Ipl. and 2 figs.). 



