5 io THE POPULAR SCIENCE MONTHLY. 



ive than the varying attitudes of the naturalist toward those local 

 modifications of species called geographical variations. 



It was early noticed that, while individuals of any one species 

 in any limited region are substantially alike, this perfect identity 

 disappears with the examination of wider extent of territory. 

 These differences were often too small to justify the formation or 

 recognition of a new species, but too evident to be wholly neg- 

 lected. These subordinate species were termed by Linnaeus varie- 

 ties, and their geographical basis was often recognized. Thus, of 

 his Homo sapiens, or aboriginal man, Linnaeus recognized four 

 varieties — asiaticus, americanus, afer, and europcBUs. As with 

 the varieties of man, so with those of other animals and plants. 

 The individuals of England were not quite those of the same spe- 

 cies in Italy, and those in America showed their own peculiarities. 



Sometimes these qualities could be exactly measured, in which 

 case a new species was described. Sometimes they proved elusive, 

 and the supposed new species were added to the great dust-heap 

 of synonymy. The work of the systematic zoologists of the last 

 generation was chiefly in museum cataloguing and labeling. To 

 them these half -tangible varieties were the object of special op- 

 probrium. On the museum shelves they were simply a nuisance, 

 obscuring the characters of the real species and throwing closet- 

 formed ideas of nature into utter confusion. Prof. Cope tells us 

 how variant shells have been crushed under the heel of the in- 

 dignant conchologist, because they would go neither into species 

 A " nor species " B." Specimens were often preserved from 

 typical localities," so that no confusion might be introduced 

 among the cherished specific characters. That Nature went on 

 producing these varying and intermediate forms was no concern 

 of the zoologist. That such forms were any part of Nature's plan 

 apparently never occurred to the followers of Linnaeus. 



Says the botanist De Candolle : " They are mistaken who sup- 

 pose that the greater part of our species are clearly limited, and 

 that the doubtful species are in a feeble minority. This seemed 

 to be true so long as a genus was imperfectly known, and its spe- 

 cies were founded on few specimens — that is to say, were provis- 

 ional only ; just as we come to know them better, intermediate 

 forms flow in, and doubts as to the limits of the species become 

 more numerous." 



The ease with which slight variations have deceived and con- 

 fused naturalists is one of the most discouraging features in the 

 history of science. Such variations have formed the basis of 

 thousands of useless and distracting names. 



When Darwin was at work upon his monograph of the bar- 

 nacles, he wrote to a friend : 



'Systematic work would be easy were it not for this con- 



te 



