LINNZUS AND NATURAL HISTORY 125 
Personal Appearance.—The portrait of Linnzus at the 
‘age of sixty is shown in Fig. 34. He was described as of 
“medium height, with large limbs, brown, piercing eyes, and 
acute vision.” His hair in early youth was nearly white, and 
changed in his manhood to brown, and became gray with 
the advance of age. Although quick-tempered, he was natu- 
rally of a kindly disposition, and secured the affection of his 
students, with whom he associated and worked in the most 
informal way. His love of approbation was very marked, 
and he was so much praised that his desire for fame became 
his dominant passion. The criticism te which his work was 
subjected from time to time accordingly threw him into 
fits of despondency and rage. 
His Influence upon Natural History.— However much we 
may admire the industry and force of Linnawus, we must 
admit that he gave to natural history a one-sided develop- 
ment, in which the more essential parts of the science received 
scant recognition. His students, like their master, were 
mainly collectors and classifiers. ‘‘In their zeal for naming 
and classifying, the higher goal of investigation, knowl- 
edge of the nature of animals and plants, was lost sight of 
and the interest in anatomy, physiology, and embryology 
lagged.” 
R. Hertwig says of him: ‘For while he in his Systema 
Nature treated of an extraordinarily larger number of ani- 
mals than any earlier naturalist, he brought about no deep- 
ening of our knowledge. The manner in which he divided 
the animal kingdom, in comparison with the Aristotelian 
svstem, is to be called rather a retrogression than an advance. 
Linnzeus divided the animal kingdom into six classes—-Mam- 
malia, Aves, Amphibia, Pisces, Insecta, Vermes. The first 
four classes correspond to Aristotle’s four groups of animals 
with blood. In the division of the invertebrated animals into 
Insecta and Vermes Linnzeus stands undoubtedly behind 
