394 



SCIENCE 



[N. S. Vol. ZLIV. No. 1133 



2. Observations on Circulating Blood. — 

 Weidenreich reported having observed cup- 

 shaped corpuscles in the mesentery of the rab- 

 bit ('02) and in the wing of the dormant bat 

 ('03). 10 Lewis ('04) drew similar conclusions 

 from a study of the guinea-pig's omentum, 

 whereas Triolo ('05) 11 recorded finding com- 

 plete spheres in this animal. Jolly ('05 et 

 seq.), 12 working on the wing of bats restored 

 from hibernation, and Schafer ('12) 13 on cer- 

 tain mammals (sp. ?) maintain that discs oc- 

 cur. Jordan ('09) 14 found both types, in ap- 

 proximately equal numbers, in the cat. 



To avoid the pressure on the vessels caused 

 by the ordinary use of a cover glass and an oil 

 immersion objective, I employed Tyrode's so- 

 lution (without a cover glass) as in the water- 

 immersion objective of former days. A Leitz 

 no. 4 dry objective and a no. 12 compensating 

 ocular, with the draw tube set at 190 mm. also 

 gave satisfactory magnification. 



The omenta of 8 cats and 2 dogs were stud- 

 ied for periods of from 1 to 4 hours. The ani- 

 mals used were in a state of deep surgical 

 shock, the anesthetic having been stopped 2 

 to 4 hours previously. Regions of the omen- 

 tum where temporary stasis has caused cor- 

 puscles to adhere in clumps or agglutinated 

 masses I do not consider favorable. Ordinary 

 circulation is much too rapid to enable one to 

 make accurate observations. It is sometimes 

 possible, however, to find a bifurcation of 

 medium sized vessels in which the rapid flow 

 selects one limb almost exclusively, separate 

 corpuscles, nevertheless, being intermittently 

 " kicked off " into the slowly moving plasma 

 of the other limb. Such a situation, where the 

 flow is rapid and normal (to find which has 

 sometimes necessitated an hour or more of 

 diligent search) I regard as most favorable for 



io Weidenreich, E., Ergeh. d. Anat. u. Entwickl.. 

 Bd. 13, pp. 1-94, 1910. 



ii Triolo, Gazz. d. ospitali, Milano, Vol. 26, p. 

 393, 1905. 



i 2 Jolly, J., Comp. rend. soc. iiol., T. 58, pp. 

 pp. 481H183, 1905. 



1 3 Schafer, E. A., "Quain's Anatomy," Vol. 2 

 Pt. 1; 11th ed., Longmans, Green & Co., London 

 8vo, 11 and 739 pp., 1912. 



ii Jordan, H. E., Anat. Anz., Bd. 34, No. 16 u. 

 17, pp. 406-412, 1909. 



study. 15 Criticisms of pressure from the 

 microscope and of observing capillaries so 

 small that the corpuscles must adjust them- 

 selves to their exiguous confines are obviated. 



Erythrocytes emerging from the main 

 stream in the way indicated were found to be 

 almost exclusively discs; most of these cor- 

 puscles are revolving when first seen and it is 

 easy to be certain of their biconcavity. In 

 such situations I have observed, and have 

 shown to my colleagues, hundreds of discs with 

 only an occasional cup- or saucer-form. 



In anesthetized guinea-pigs and rabbits cups 

 were very common, and in a dog, under ether 

 anesthesia, a great preponderance of cup- 

 shapes were observed. Is the anesthetic re- 

 sponsible for the cup-shape? The following 

 experiment is highly suggestive. A hanging 

 drop preparation of human blood, or of the 

 blood of a cat or dog, diluted with serum is 

 made. If a drop of ether or chloroform be 

 introduced into the bottom of the cell, the 

 drop takes on the vapor and the discs are seen 

 to change rapidly first to shallow cups, then to 

 deep cups and spheres. 



I believe that my observations indicate that 

 the erythrocytes of normal circulating mam- 

 malian blood are biconcave discs, the burden 

 of proof resting on those who have used an- 

 esthetized animals to show that the anesthetic 

 held in the blood is not responsible for the pre- 

 ponderance of cups observed. 



3. Action of Fixitives. — Many workers have 

 recorded that mammalian tissues, preserved in 

 various standard fixatives, contain cup-shaped 

 erythrocytes. Should great weight, however, 

 be given evidence of this sort? These cor- 

 puscles are plastic structures of extreme deli- 

 cacy, mere contact with adjacent corpuscles or 

 with obstacles sufficing, when gentle streaming 

 is induced, to cause excessive and varied tem- 

 porary distortions. Fixation is essentially a 

 coagulation process and it has been shown that 

 the so-called best fixatives actually diminish 

 the diameter of the corpuscle. If, therefore, 

 the reagent does not act on all sides of an 

 erythrocyte simultaneously is not a buckling 

 of the side first fixed to be expected? Indeed 



is For making these observations I can particu- 

 larly recommend the dog's omentum. 



