I/O HEROES OF SCIENCE. 



as he soon saw that some had red blood. Lamarck 

 worked very hard in describing and grouping the 

 genera, and gradually modified the zoology of 

 those lower forms of life. First of all he classified n 

 them by their anatomy, and then, after about / 

 fifteen years' labour, remodelled his classification, / 

 and published a system of invertebrata, containing/ 

 the classes, orders, and genera of the animals, men-/ 

 tioning their most important anatomical characters] 

 In this book he, for the first time amongst zoolo- 

 gists, began with the most simple and least highly 

 organized animals, the converse having been the 

 method previously. There was a reason in this 

 that will be noticed further on. Out of the con- 

 fusion of old he made the great groups appear 

 clear and well defined. Thus from amongst the 

 insects he separated the Crustacea or crab tribe, 

 and he introduced that of the arachnida or spiders. 

 Then he described and limited a class of worms 

 called by him annelida ; moreover, he placed the 

 microscopic infusoria in a class by themselves, and ~ 

 removed them from the jumble of the polypes. 

 His work extended into the moUusca, both bivalve 

 and univalve ; he named many genera and species 

 of corals, and in every group showed a master 

 mind. The fossil shells found in such abundance at 

 this time, in the neighbourhood of Paris, attracted 

 his attention, and he laboured on their description 

 and explanation. In fact, the enormous labours of 

 Lamarck consolidated the zoology of the lower 

 animals, and his writings became the text-books of 



