204 THE MINUTE ANATOMISTS 



Leeuwenhoek demonstrated the capillary flow more 

 advantageously by using the tail of the tadpole and fish, 

 the web of the frog's hind foot, the membrane of the 

 bat's wing, &c. Malpighi in 1665 (supra, p. 163) had 

 seen the red blood-corpuscles of the hedgehog, mistaking 

 them however for fat-cells ; Swammerdam at some 

 unknown date [supra, p. 198) had found them in the 

 blood of man and of the frog; Leeuwenhoek in 1673 

 examined a drop of his own blood, and saw red corpuscles 

 floating in it ; his discovery was published in 1674. He 

 went on to show that the mammals examined by him 

 contained circular red corpuscles, the birds, amphibians 

 and fishes oval ones ; that the frog's corpuscles are 

 nearly colourless, but reddish when superposed, and 

 exhibit a bright oval spot in the centre ; further, that 

 the redness of blood is due to their presence. He also 

 found uncoloured corpuscles circulating in small trans- 

 parent crustaceans. 



Spermatozoa 



None of Leeuwenhoek's own discoveries made quite 

 so much stir in the scientific world as the discovery of 

 the spermatozoa, which was popularly attributed to him. 

 He tells us^ that in the year 1677 a young physician 

 named Hamm demonstrated the spermatozoa in his 

 presence ; Leeuwenhoek lost no time in transmitting 

 the news to scientific friends and to the Eoyal Society. 

 He supplied figures of the spermatozoa, some of them 

 ludicrously like human beings, with heads, arms and 

 legs.^ It was Leeuwenhoek's belief throughout life that 



1 Phil. Trans. No. 142 (1678). The name of the discoverer is quoted by 

 Leeuwenhoek as " Dominus Ham," by others as Ludwig van Hammen, who is 

 said to have been a pupil of Leeuwenhoek and to have used a microscope 

 made by him, and again as Stephen Hammen of Stettin. 



2 Oont. Arc. Nat., Vol. Ill, p. 68. 



