392 



SCIENCE 



[N. S. Vol. XLIV. No. 1133 



author has employed a loose form of state- 

 ment — for instance, he speaks of " physiolog- 

 ical sensations" (p. 162), and he employs the 

 term color throughout in an equivocal and 

 confusing fashion, sometimes referring to 

 color-stimulus and sometimes to color-sensa- 

 tion; a few inaccuracies of statement are also 

 to be found, of which perhaps the most serious 

 is the assertion that the extreme peripheral 

 region of the retina is totally color-blind (p. 

 71; p. 258). Although the book will be of 

 doubtful service to elementary students, it may 

 safely be recommended to more advanced 

 workers as a supplement to the earlier and 

 more critical summaries by Mrs. Ladd-Erank- 

 lin and others in Baldwin's " Dictionary," and 

 by Eivers in Schafer's " Text-Book of Physi- 

 ology." 



J. W. Baied 

 Clark University 



SPECIAL ARTICLES 



THE MAMMALIAN ERYTHROCYTE— A BICON- 

 CAVE DISC 1 



The existence of " bell "- or " cup "-si 

 red corpuscles in mammalian blood has been 

 recorded frequently since the early observa- 

 tions of Leeuwenhoek (1719). 2 The serious 

 proposal that the cup, and not the classic bi- 

 concave disc, is to be considered normal is, 

 however, a comparatively recent teaching 

 which has been received with considerable 

 skepticism. Since these concavo-convex cor- 

 puscles may be found in drawn blood, in fixed 

 tissues, and even in circulating blood, the issue 

 obviously hinges on the determination of which 

 is the normal and which the derived form — one 

 or the other representing a modification. 



1. Examination of Drawn Blood. — It has 

 been claimed (Weidenreich, '02, 3 et seq. ; 

 Lewis '04) 4 that drawn blood examined im- 



i From the Anatomical Laboratory of the North- 

 western University Medical School, Contribution 

 No. 43, July 2, 1916. 



2 Leeuwenhoek, A., ' ' Epistolse physiologies, ' ' 

 epistola 44, 1719. 



3 Weidenreich, F., Arch. f. mile. Anat., Bd. 61, 

 pp. 459-507, 1902. 



4 Lewis, F. T., Jour. Med. Research, Vol. 10 (N. 

 S., 5), pp. 513-517, 1904. 



mediately on a warm slide is favorable for the 

 demonstration of cups. According to this 

 view, the assumption of the familiar disc-shape 

 depends on an almost instantaneous change 

 due to the evaporation and concentration of 

 plasma before the preparation can be made 

 and examined. 



That the disc-form is normal has been as- 

 serted by Jordan ('15) 5 working with blood, 

 diluted with physiological solutions, in cul- 

 ture slides, and by Lohner ('10)° who em- 

 ployed a cabinet of sufficient size to contain a 

 microscope and to permit the free use of his 

 hands, introduced through appropriate open- 

 ings. Within this apparatus, heated to 38° O. 

 and saturated with moisture, blood was drawn 

 from the finger and examined. Lohner re- 

 ports that the blood corpuscles were " stets und 

 ausschliesslieh " biconcave discs. 



In ordinary warm slide- and cover-prepara- 

 tions, made as quickly as possible, I have ob- 

 served a few cups only, but have never fol- 

 lowed the transformation of these into discs 

 as the newer hypothesis suggests. The momen- 

 tary exposure to air necessitated in making 

 ordinary preparations may be practically elim- 

 inated by utilizing the following method. 

 Superimposed cover glasses, separated by a 

 hair, are fused at one point by heat ; if an edge 

 be now applied to a needle prick in the finger, 

 and the finger squeezed, the issuing blood is 

 drawn in by capillarity. Such preparations, 

 examined quickly, have never yielded evidence 

 for the general existence of the cup-shape. A 

 few cups may usually be found, whereas scores 

 of indubitable discs appear. 



Since the experiments of Banvier, in 1875, 7 

 it has been known that graded temperatures 

 can alter disc-shaped corpuscles to shallow 

 cups, thick-walled cups or even to spheres — ■ 

 e. g., typical cups are found exclusively when 

 blood is warmed to 55° C. (Zoth). s Is it pos- 

 sible that some investigators, who advocate the 



5 Jordan, H. E., Proc. Soc. Exp. Biol, and Med., 

 Vol. 12, No. 7, pp. 167-169, 1915. 



6 Lohner, L., Arch. f. gesam. Physiol., Bd. 131, 

 pp. 408-424, 1910. 



7 Banvier, L., "Traits technique d 'Histologie, " 

 1st ed., Paris, 1875. 



s Zoth. Vide Lohner, op. cit. 



