Ii8 GENERAL ORNITHOLOGY part ii 



it is difficult to predicate " high " or " low" within such a narrow 

 scale. The great group Passeres, for example, comprehending a 

 majority of all known birds, is scarcely more different from other 

 birds than are the families of reptiles from each other, and among 

 Passeres we have little to go upon in deciding "high" or "low" 

 beyond the musical ability of Oscines. It is hard to see much 

 difference in actual complexity of organisation between those birds 

 regarded as the lowest, as an ostrich or a penguin, and those con- 

 ceded to be highest, as a swallow or sparrow. Nevertheless, in a 

 larger perspective, as between a fish, a reptile, and a bird, the 

 student will readily perceive the bearing of the ideas attached to 

 the terms " low " and " high " in the scale of organisation Creatures 

 rise in the scale by a number of correlated modifications and in the 

 course of time (for it takes time to evolve a class of birds from 

 sauropsidan stock as really as it does to develop the germ of an egg ' 

 into the body of a chick). Progressive differentiation and specialisa- 

 tion of structure and function in due course elaborates diversity 

 from sameness, complexity from simplicity, the " high " special from 

 the " low " general plan of organisation ; the culmination in man of 

 the vertebrate type, first faintly foreshadowed in the embryonic 

 Ascidian. No one should venture to foretell the result of infinit 

 esimal increments in elevation of structure and function, nor pre- 

 sume to limit the infinite possibilities of evolutionary processes, 

 either in this actual world or in a foretold next one. 



As to " evidences of design " in the plan of organised beings, it 

 may be said simply that every creature is perfectly " designed " or 

 fitted for its appropriate activities, and perfectly adapted to its 

 conditions of environment. In fact, it must be so fitted and 

 adapted, or it would perish. "Whether it so determines itself, or is 

 so determined, is a teleological question. The truth remains that 

 every creature is perfect in its own way. A worm is as perfectly 

 fitted to be a worm, as is a bird to be a bird ; in fact, were it not, 

 it would either turn into something else, or cease to be. A spade 

 is as perfect an organisation of the spade kind, as is the steam-engine 

 of that kind of an organisation ; though the difference in complexity 

 of structure and functional capacity, like that between the lowly 

 organised ascidian generality and the highly organised avian 

 speciality, is enormous. 



One word more : The class of mammals is highest in the scale 

 of organisation. The class of birds is next highest. But it does 

 not follow, from this relation sustained by Mammalia and Aves 

 collectively, that every mammal must be more highly organised 

 than every bird. It is difficult to say how a mole or a mouse is a 

 more elaborate or more capable creature than a canary-bird, physic- 

 ally or mentally. The relative rank of two groups is determined 



