42 Qen. Sub. 
I. GENERAL SUBJECTS. 
Relations of hydrostatic and respiratory functions in aquatic animals ; 
Marcacci (326). 
The air and life ; Yarigny (544). 
Excretory function of mid-gut in worms : In Dinophilus , Polynoidce , 
Phyllodoce maculata , Priapulus , &c., pigments ( e.g indigo-carmine, 
safranin) are taken up from the gut into vacuole-like granules in the 
epithelial cells of the mid-gut ; Sciiimkewitsch (493). 
Excretion in suail : The vesicle and ureter receive venous blood, the 
uric gland itself receives arterial blood. The vesicle is an alkaline gland, 
changes into urate of soda the uric acid excreted by the kidney; Girod 
(191). 
Excretion in snails : Uric acid is eliminated as such ; the transforma- 
tion into urates denied ; Cuenot (103). 
Excretory granules in Infusorians ; Sciiewiakoff (492). — Phagocytic 
function of hepatic vessels in crayfish ; Saint-Hilaire (480). 
Criticism of Cuenot’s physiology of Decapods ; Saint-Hilaire (481). 
Mid-gut gland of Decapod Crustaceans : It absorbs food ; excretes 
injected pigment ; regulates composition of the blood, &c . ; Saint- 
Hilaire (481). 
Environment, influence of; CuriNOT (106). — “Organs of relation” in 
Vertebrates ; Ciiatin (90). 
Development and probable function of the thymus. The thymus is 
part of the lining of the gill-clefts (5 Anlagen in Raja, 4 in Teleosteans, 
and a decreasing number as we ascend the series). It is a lymphoid 
orgau specially differentiated from the hypoblast of the gill-clefts, with 
its original elements converted into leucocytes, which probably serve for 
the protection of the gills ; Beard (27). 
Study of lymphatic glands of Invertebrates by injecting bacteria ; the 
results show frequent phagocytic function ; Kowalevsky (285). 
Physiology of compound eye of insects : (1) Even in darkness there is 
periodic displacement of pigment, probably, therefore, a sleep pheno- 
menon. (2) Displacement of pigment used as a test of the range of rays 
to which an insect’s eye is sensitive ; thus ultra-red rays are felt. (3) 
Explanation of the fact that a small visual angle is sufficient for percep- 
tion of surroundings, and that the insect is thus saved from being blinded 
in bright light; Kiesel (269). 
Physiology of composite eye : Its adaptation to close vision, its limits 
in defining objects at a distance ; Mallock (324). 
Light-sense in eyeless animals: The skin of Amphioxus, apart from 
pigment spot, is diffusely and keenly photoskioptic, i.e., responsive to 
suddeu illumination, but not skioptic, i.e., responsive to shade. Spiro- 
graphis spallanzanii markedly skioptic ; Ciona intestinalis photoptic not 
skioptic ; Cereanthus membranaceus the same ; Adamsia and A nemonia 
neither skioptic nor photoptic ; Helix pomatia and H. hortensis diffusely 
photoskioptic (apart from iconoptic eyes), II. arbustorum (darkly 
pigmented) shows weaker reaction, night snails Btill weaker; Unto pic- 
torum keenly skioptic and photoskioptic, &c. ; Nagel (383, 384). 
