572 MERISTIC VARIATION. [PART I. 



principles with which we are all t'ainiliar. Upon the special 

 fallacy of the belief that great Variation is much rarer in wild than 

 in domesticated animals we have often had occasion to dwell. As 

 was pointed MIII in the discussion of tin- evidence on Teeth (p. 2GG) 

 this belief arises from the tact that domesticated animals are for 

 the most part variable, and that we have every opportunity of ob- 

 serving and preserving their variations. To compare rightly their 

 varialiility with that of wild animals choice should be made of 

 animals that are aNo variable though wild. Taken in this way the 

 comparison is fair, and as 1 have already >aid. if we examine the 

 variation in the vertebra:' of the Sloths, in the teeth of the Anthro- 

 poid Apes, in the colour of the Dog-whelks (Purpura lapillus), *v-., 

 we find a fiv . (iieney and a range of Variation matched only by 

 the most variable of domesticated animals. 



It is needless to call attention to the fact that in hardly any 

 cases even of extreme variat ions in wild creatures is there evidence 

 that the animal wa^ unhealt hy, r ill nourished, or that its economy 

 was in any visible way upset ; but in almost every example, save 

 for the variation, the body had the appearance of normal health. 



A tier all that has been said few perhaps will still ask us to 

 believe that the fixity of a character is a measure of it> importance 

 to the organism. To try to apply such a doctrine in the open air 

 of Nature leads to absurdity. Let one more case be enough. I go 

 into the fields of the North of Kent in early August and I sweep 

 the Ladybirds off the thistles and nettles of waste places. Hun- 

 dreds, sometimes thousands, may be taken in a few hours. They 

 are mo>tly of two species, the small Cocdnella decempunctata or 

 i'iiri(ilii/in and the larger C. septempunctata . Both are exceedingly 

 common, feeding on Aphides on the same plants in the same places 

 at the same time. The former (C. decempunctata) shews an ex- 

 cessive variation both in colours and in pattern of colours, red- 

 brown, yellow-brown, orange, red, yellowish-white and black, in 

 countless shade>, mottled or dotted upon each other in various 

 ways. The colours of pigeons or of cattle are scarcely more variable. 

 Yet the colour of the larger C. septein/xaictatu is almost absolutdy 

 conMant. having the >ame black spots on the same red ground. 

 The slightest difference in the size of the black spots is all the 

 variation to be seen. (It has not even that dark form in which 

 the blac"k spreads over the elytra until only two red spots remain, 

 which is to be seen in C. l>ij>iuirt</t<i.) To be asked to believe that 

 the colour of C. septempunctata is constant because it matters to 

 the species, and that the colour of C. decempunctata is variable 

 because it does not matter, is to be asked to abrogate reason. 



But the significance of the facts does not stop here. When, 

 looking further into the variations of (.'. decempunctata it is found 

 that most of its innumerable .shades of variation are capable of 

 being grouped round some eight or ten fairly distinct types, surely 



