Isotely and Coralsnakes. 5 



even in tlie same iiidividual iu the successive regions of tlie body 

 and tail. 



The above propositions, and others, will be discussed in the 

 following- pages, after a description of the evoliition of some of the 

 more important colour-patterns which might be considered to be 

 warning colours and therefore worth imitating. It is as well to 

 mention that most of the respective genera, Elaps as well as the 

 others. comprise some species which have a piain brownish or dark 

 dress, without any conspicuous colouration. 



There are two types of pattern and colouration, or rather niodes 

 of procedure, in each of which the variations can be so arraugend 

 as to represent an apparently evolutionary series. That they are 

 not fundamentally different is showu by the occurence of both, or 

 either in the same species. 



DM. TheMelanisticserieswithDonbleblackrings.^) 

 In the typical condition the pattern consists of broad red bands 

 which are separated by a triad of two black rings divided by a 

 yellow ring. A further diagnostic feature is that the red and black 

 are always neighbours, but never red and yellow. 



This series begins with a longitudinal row of darker dorsal 

 patches upon an indifferent xanthic (yellowish-fuscous-olive) ground 

 colour. The races of some of the North American CoroneUa doliata, 

 sometimes also the iiidividual changes from youth to age, show 

 how a pattern of repeated darker and paler rings is produced by 

 the distension of the original patches. The dark patches follow 

 the principle of growing ocelli. They alone contain, or receive 

 melanine which in the widening, growing ocellus assumes a peripheral 

 Position and then concentrates into narrow black curves, which are 

 ultimately transformed into regulär transverse rings, by the time 

 that the ocellus has either 'burst', or reached the ventral side. The 



1) It is remarkable that this typical pattern, two black rings divided 

 by a yellow ring, is not known to occur in any Elaps and yet it is the 

 pattern , or stage , out of which the complicated combination DM. 5, cf. 

 also Table I, 7, seems to have been evolved. On the other band it is 

 difficult to account by it for the pattern of Elaps decoratus , E. elegans 

 and E. flliformis, cf. Table I, 8, in which the three black rings together 

 with the two yellow rings are ofteu so narrow that the five rings together 

 are less broad than one red band. However the length of the "seg- 

 raents" varies much , witness the proportions of black and yellow in the 

 various tails figured. 



