Lefevre — The Advance of Zoology in the Nineteenth Century. 75 



anatomy, with the resulting discovery of the red blood-cor- 

 puscles in vertebrates, the cross-striation of muscular fibre, 

 the fibres of the lens of the eye, the spermatozoon, and many 

 other important facts of microscopical structure. 



In the latter part of the sixteenth century and the begin- 

 ning of the seventeenth, interest had arisen in the structure 

 and life-history of particular groups of animals, the develop- 

 ment of which was greatly stimulated by the discovery and 

 description of interesting forms of animal life from distant 

 countries. There soon arose a body of facts which made 

 possible a systematic classification of animals and plants, 

 based upon their anatomical structure, which was to reach 

 its culmination in the work of the Swedish naturalist, Lin- 

 naeus. The chief name between the time of Gesner and Lin- 

 naeus in systematic zoology is that of John Ray, who paved 

 the way for his illustrious successor and who is prominent 

 from the limitation which he set upon the term species 

 previously only vaguely applied. The meaning which he 

 placed upon the term remained until Darwin gave it a new 

 significance. 



Linnaeus was born in 1707 and died in 1778, and in his 

 great work, the " Systema Naturae," first published in 1735 

 and passing through twelve editions before his death, he laid 

 the foundation of modern systematic zoology. In place of 

 loose and rambling descriptions he introduced concise, brief 

 diagnoses, adding numerous discoveries in the anatomy of 

 plants and animals and descriptions of many new species. 

 But his chief merit lies in the fact that he inaugurated a 

 method of classification which practically created systematic 

 zoology and botany in their modern form. Before Linnaeus 

 long, many-worded names had been used and no uniformity 

 existed, but by the introduction of his system of binomial 

 nomenclature it became possible to speak of any given animal 

 or plant with accuracy and to express in a single phrase re- 

 semblances and differences between species. Hitherto much 

 confusion had arisen from the use of common names in the 

 scientific world, and furthermore from the fact that one and 

 the same animal or plant might have different names, or dif- 

 ferent animals and plants the same name. In Linnaeus' 



