ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 287 



the melanophores by means of the spinal and sympathetic nerves. The 

 nerve-endings for the reception of indirect light stimuli are in the retinae, 

 sensory nerve-endings in the skin probably paying no part. 



Acidophilous Chromosomes and Chromatin Particles." — Ivan 

 E. Wallin found in sections of lamprey larvae, 5 mm. in length, that 

 numerous mesenchyme and blood-cells contained nuclei staining a 

 uniform and brilliant red. These were scattered among other cells 

 having similar nuclei, but staining the usual deep blue colour with the 

 hematoxylin eosin stain. The cells with the red-stained nuclei showed 

 mitotic division like the others ; in some cases both kinds of chromatin 

 were present in the same cell. The author believes this is the first 

 record of a case where the chromosomes in a dividing-cell have 

 definitely taken on the acid stain. 



Blood Counts for Animals.f— J. J. Wells and J. E. Sutton, jun., 

 liave counted the blood-corpuscles in a variety of types. No general 

 statement can be made, covering all animals, regarding the effect of 

 age on the number of erythrocytes. The average number of red and 

 white corpuscles, respectively, per cubic cm., was as follows :— Adult dog, 

 (>,709,;^0U red and 11,000 white ; young puppy, 4,2G8,560 and 16,290 ; 

 cat, 9,046,000 and 14,800; rabbit, 6,800,850 and 11,743; horse, 

 7,894,000 and 8,600; cow, 7,655,850 and 11,600; sheep, 10,354,000 

 and 8,533 ; and so on ; adult badger, 13,995,200 and 16,220 ; 

 three-months' badger, 7,880,000 and 14,100 ; the same badger 4i months 

 old, 11,440,000 and 10,650 ; turtle {Ghrysemys eUgans), 756,000 and 

 12,330 ; frog {Rami esculenta), 591,000 and 10,400. Ic may be recalled 

 that the number of erythrocytes per cubic cm. is about 5,000,000 for 

 man and 4,500,0000 for woman. 



Fat and Mitochondria in Cardiac Muscle.^ — H. Hays Bullard 

 finds that the cardiac muscle fibres of Mauunals, both foetal and adult, 

 contain a variable nutritive reserve in the form of droplets of neutral 

 fat, in longitudinal and transverse rows between the myofibrilla; or 

 muscle columns. Fibres with little fat (light by transmitted light) 

 occur side by side with others crowded with droplets (dark by 

 transmitted light), and correspond to the so-called light (non-fatty) 

 and dark (fatty) fibres of skeletal muscle. In inanition the visible fat 

 of cardiac muscle decreases, with fatty foods it increases. The 

 phospholipine (lecithin and related compounds) of cardiac muscle is 

 found in the true interstitial granules (mitochondria), and it is not 

 markedly decreased in inanition, or increased when fats are given in 

 the food. Neutral fat droplets in cardiac muscle do not arise from true 

 interstitial granules. Visible neutral fat is of normal occurrence in the 

 muscle fibres of the bundle of His ; only a small amount is found on 

 the nodal tissue of the heart. 



* Anat. Record, ix. (1915) pp. 421-4 (1 pi.) 



t Amer. Journ. Physiol., xxxix. (1915) pp. 31-6. 



X Amer. Journ. Anat., xix. (1916) pp. 1-34 (2 pis.). 



X 2 



