238 CAUSES OF VARIABILITY. Chap. XXII. 



Those authors who "believe that it is a law of nature that 

 each individual should differ in some slight degree from every 

 other, may maintain, apparently with truth, that this is the 

 fact, not only with all domesticated animals and cultivated 

 plants, "but likewise with all organic "beings in a state of 

 nature. The Laplander by long practice knows and gives 

 a name to each reindeer, though, as Linnaeus remarks, " to 

 distinguish one from another among such multitudes was 

 beyond my comprehension, for they were like ants on an ant- 

 hill." In Germany shepherds have won wagers by recog- 

 nising each sheep in a flock of a hundred, which they had 

 never seen until the previous fortnight. This power of 

 discrimination, however, is' as nothing compared to that 

 which some florists have acquired. Yerlot mentions a 

 gardener who could distinguish 150 kinds of camellia, when 

 not in flower ; and it has been positively asserted that the 

 famous old Dutch florist Toorhelm, who kept above 1200 

 varieties of the hyacinth, was hardly ever deceived in knowing 

 each variety by the bulb alone. Hence we must conclude 

 that the bulbs of the hyacinth and the branches and leaves 

 of the camellia, though appearing to an unpractised eye 

 absolutely undistinguishable, yet really differ. 1 



As Linnaeus has compared the reindeer in number to ants. 

 I may add that each ant knows its fellow of the same com- 

 munity. Several times I carried ants of the same species 

 (Formica rufd) from one ant-hill to another, inhabited 

 apparently by tens of thousands of ants ; but the strangers 

 were instantly detected and killed. I then put some ants 

 taken from a very large nest into a bottle strongly perfumed 

 with assafoetida, and after an interval of twenty-four hours 

 returned them to their home ; they were at first threatened 

 by their fellows, but were soon recognised and allowed to 

 pass. Hence each ant certainly recognised, independently of 

 odour, its fellow ; and if all the ants of the same community 

 have not some countersign or watchword, they must present 

 to each other's senses some distinguishable character. 



1 ' Des Jacinthes,' &c, Amsterdam, lated bv Sir J. E. Smith, vol. i. p. 



1768, p. 43; Yerlot, 'Des Varietes,' 314. The statement in regard to 



&c, p. 86. On the reindeer, see German shepherds is given on th^ 



Linnaeus, 'Tour in Lapland,' trans- authority of Dr. Weinland. 



