as indicating Affinities of Species, 405 



removed ; as may be exemplified by adducing the bill of the 

 crossbill, modified in direct relation to the seminiferous cones 

 of the Coniferse ; or the recurved bills of certain humming 

 birds, to the bent tubes of the corollas of particular Bignon- 

 idcece, &c. Physiological relations are all resolvable into 

 mere resemblance ; because every species is essentially distinct 

 and separate from every other species; otherwise it would not 

 be a species, but a variety. The most similar species, there- 

 fore, are only allied to each other in consequence of the close 

 resemblance of their general organisation ; the degree of 

 affinity being greater or less, according to the extent of that 

 resemblance (according to the degree of their physiological, 

 not their mere apparent, similitude) ; in short, according as 

 they are more or less framed upon the same general or typical 

 plan; which plans not only regulate the minutiae of structure 

 in those species which are organised upon them, but, to a 

 very considerable extent, even their colours and markings. 



Of course, the observation here very naturally suggests 

 itself, that, if the colours and markings of species have a de- 

 finite use (which, in some instances, is sufficiently obvious 

 even to our comprehension), then, we might reasonably expect 

 to find that resemblance which is found to subsist between 

 those of species whose habits are almost the same. 



True ; but, then, there are many trivialities observable in 

 the marking of allied species, which can only be explained 

 upon the principle that they are modifications of some particular 

 general or typical plan, of markings, as well as of structure. 

 Such is the pale line along the head of the newly discovered 

 Dalmatian, iZegulus modestus Gotdd, in place of the bright- 

 coloured coronal feathers of its different congeners ; which is 

 exactly analogous to the curious fact, that the apparent rudi- 

 ments of dentition exist in the gums of the fcetal toothless 

 whales ; sufficiently intimating that these latter animals are 

 modifications merely of some general typical plan, of which 

 one of the leading characters is to be furnished with teeth. 

 So, also, might be adduced the tiny, soft, deflected spine 

 situate at the bend of the wing of the common gallinule, in 

 like manner indicating that this species, also, is framed upon 

 some particular plan of structure, the more characteristic 

 examples of which have spurred wings, as we find to be the 

 case in the allied genus JParra. In all the species organised 

 upon any given type, we may always look for some trivial 

 resemblances of this kind ; we may always expect to find some 

 traces of any particular structure or markings, which are ob- 

 servable in those typical forms of which the others are but 

 modifications ; the probability of this, of course, increasing 



