74 STRUCTURE OF COLORED BLOOD-CORPUSCLES. 



which were really only incidental while investigating the struct- 

 ure, the main object of my researches have been anticipated 

 by previous investigators. One saw, and reported as an extraor- 

 dinary finding, one or more forms or active form-changes like 

 those I have described ; another others ; some a far greater num- 

 ber than I. " Fehlt leider nur das geistige Band." The band 

 which connects and explains the phenomena observed is the 

 discovery of the structural arrangement. 



In the following historical sketch of points bearing on my 

 observations, I shall refer to a few only of the legion who 

 have made colored blood-corpuscles the subject of their investi- 

 gation. 



More than a hundred years ago, William Hewson, after asserting that the 

 red corpuscles are of different sizes in different animals, added : "I have like- 

 wise observed that they are not all of the same size in the same animal, some 

 being a little larger than others/'* etc. Hewson's editor, Gulliver, who has made 

 a very large number of measurements of red blood-corpuscles of different 

 animals, and is "our highest authority upon the subject," said of his own 

 elaborate tables : "We are only speaking now of the average size, for they vary 

 like other organisms ; so that in a single drop of the same blood you may find 

 corpuscles either a third larger or a third smaller than the mean size, and 

 even still greater extremes" ; t and more recently,! " But as I have long since 

 shown, the corpuscles in one species of the vertebrate class, as seen in a 

 single individual thereof, vary so much in size that their average dimensions 

 cannot be determined with absolute precision; and were this fact kept in 

 view much needless discussion might be spared." 



Beale, also, long ago called attention to the fact that "corpuscles may be 

 found which are not more than the fifth or sixth of the size of an ordinary 

 blood-corpuscle. " Again : " The red corpuscles vary in size, and more than is 

 usually supposed "; || and again: "It is generally stated that the red blood- 

 corpuscles of an animal exhibit a certain definite size ; but it will be found 

 that they vary extremely, so that corpuscles exist of various dimensions." H 



Welcker ** found in the blood of Dr. Schweigger-Seidel colored blood-cor- 

 puscles as small as. 0051, and as large as .0085 mm. Altogether, the inini- 



* "Philosophical Transactions," vol. Ixiii., Part n., p. 320 (read June 24, 1773). The works 

 of William Hewson, F. R. S., Edited, with an Introduction and Notes, by George Gulliver, 

 F. R. S., London. Published by the Sydenham Society, 1846 ; p. 234. 



t " Lectures on the Blood of Vertebrate." Medical Times and Gazette, vol. ii. of 1862, 

 p. 157. 



t "Comparative Photographs of Blood-disks." Monthly Microscopical Journal, Novem- 

 ber, 1876, p. 240. 



I " Archives of Medicine," vol. ii. (No. 8), p. 236, and Quarterly Journal of Microscopical 

 Science, April-May, 1861 ; p. 249. 



II " Observations upon the Nature of the Bed Blood-corpuscles." Transactions of the 

 Microscopical Society of London (read Dec. 9, 1863), vol. xii., N. S., p. 37. Quarterly 

 Journal of Microscopical Science, Jan., 1864. 



T " The Microscope in its Application to the Practice of Medicine," third edition. Re- 

 published in Philadelphia, 1867 ; p. 170. 



** " Grb'sse, Volum und Oberflache und Farbe der Blutkb'rperchen bei Menschen und bei 

 Thieren." Zeitschrift fur rationelle Medicin, S. iii., vol. xx. (1863), p. 237. 



