86 BIOLOGY AND ITS MAKERS 
mammals circular. He reserved the term ‘globule’ for 
those of the human body, erroneously believing them to 
be spheroidal. 
Other Discoveries.—Among his other discoveries bear- 
ing on physiology and medicine may be mentioned: the 
branched character of heart muscles, the stripe in voluntary 
muscles, the structure of the crystalline lens, the description 
of spermatozoa after they had been pointed out to him in 
1674 by Hamen, a medical student in Leyden, ete. Richard- 
son dignified him with the title ‘the founder of histology,’ 
but this, in view of the work of his great contemporary, 
Malpighi, seems to me an overestimate. 
Turning his microscope in all directions, he examined 
water and found it peopled with minute animalcules, those 
simple forms of animal life propelled through the water by 
innumerable hair-like cilia extending from the body like 
banks of oars from a galley, except that in 
many cases they extend from all surfaces. 
He saw not only the animalcules, but also 
the cilia that move their bodies. 
He also discovered the Rotifers, those 
favorites of the amateur microscopists, made 
so familiar to the general public in works 
like Gosse’s Evenings at the Microscope. 
He observed that when water containing 
these animalcules 
evaporated they were 
reduced to fine dust, 
but became alive 
again, after great 
lapses of time, by the 
introduction of water. 
Fic. 21.—Plant Cells. (From Leeuwen- He made many 
hoek’s Arcana Nature.) observations on the 
