20.4 BIOLOGY AND ITS MAKERS 
vesicles and cye-pockets. His delineation of heart, brain, 
and eye-vesicles are far ahead of those illustrating Wolff’s 
Theoria Gencrationis, made nearly a hundred years later. 
Fig. 61 shows a few selected sketches from the various 
plates of his embryological treatises, to compare with those of 
Wolff. (See Fig. 63.) 
The original drawings for De Ovo Incubato, still in pos- 
session of the Royal Society, are made in pencil and red chalk, 
Fic, 62.—MaRcELLO MALPIGHI, 1628-1694. 
and an cxamination of them shows that they far surpass the 
reproductions in finish and accuracy. 
While Harvey taught the gradual formation of parts, 
Malpighi, from his own observations, supposed the rudiments 
