242 SUMMARY OF CURRENT RESEARCHES RELATING TO 



"before and during the sleep. In full hibernation there is a slight (5 p.c.) 

 increase in the number of red blood corpuscles ; the number of leucocytes 

 is reduced to a half. In half-sleep, with the temperature intermediate 

 between that of activity and that of hibernation, there is a notable 

 increase in the number of red blood corpuscles, the quantity of hsemo- 

 globin, and the specific gravity ; the white blood corpuscles are twice as 

 abundant as in the wideawake state and four times as abundant as in 

 complete hibernation. In the transition period there is a peculiar state 

 of activity. On wakening, but before eating, the animal shows a 

 condition of the blood like that of half -sleep, except that the number of 

 leucocytes approaches the normal. The size of the red blood corpuscles is 

 not changed during hibernation. The number of mononuclear leucocytes 

 is somewhat reduced in relation to the number of polynuclear leucocytes. 



J. A. T, 



Nerve-cells of Woodchuck during Hibernation, — Andrew T. 

 Easmussen {Proc. Amer. Assoc. Anatomists, in Anat. Record, 1919, 16, 

 160-1). In Marmota mo7iax the mitochondria in the chief cells of 

 the brain and spinal cord show no noticeable change in number, size, 

 shape, or grouping during hibernation. Five adult animals were exa- 

 mined before hibernation began, five towards the end of the dormant 

 period, and five at various intervals after waking up and becoming active. 



J, A, T. 



Luminous Animals, — Ulrio Dahlgren {Year-loolc, Carnegie Insti- 

 tution, 1918, 17, 157-8), An account of a collecting expedition, referring 

 to Cteuophores, Noctiluca, an apparently luminous dolphin ("a moving 

 luminous body with a diminishing trail of several yards "), some luminous 

 Collembolids, the firefly Photuris pennsylvanica, an earthworm {Micro- 

 scolex) " with an autogenous organic light in response to well-known 

 stimuli," luminous mycelia in decaying wood, the firefly Pyractomena 

 borealis, a species of Phengodes, and so on. Of a firefly (Phausis) in 

 Alabama it is noted that the light is very distinctly blue, and that the 

 adult female is a white wingless grub with multiple lights on all surfaces. 

 The luminous organ is of the simple two-layered type, without " ovals," 



J, A, T. 



Death from High Temperature, — Alfred Goldsborough Mayer 

 {Amer. Journ. Physiol., 1917, 44, 581-5). Experiments were made 

 with reef-corals kept in warm sea-water. The fatal temperature for 

 different species was determined ; it varied from 34° "7 C. to 38° '2 0. 

 Those corals which live in cool, relatively agitated water free from silt 

 are those that cannot withstand high temperatures, whereas those which 

 live in the hot, silt-laden shallows near shore are generally speaking 

 resistant. What causes death ? The fatal temperature is too low for 

 the coagulation of most if not all proteids ; when killed the animals are 

 fully relaxed ; moreover, coagulated proteids could not readily be elimi- 

 nated when the animal was restored to water at normal temperature, 

 coagulation being practically non-reversible. Nor is death at high 

 temperature due to asphyxiation, for the experiments showed that there 

 is no direct relation between the oxygen supply and the fatal tempera- 



