NATURAL HISTORY — ZOOLOGY. 209 



sure to self-fertilize in the first generation, — where every desirable variation 

 is watched for and cared for, and kept separate ; and it may be confidently 

 inferred that they vary in cultivation, at first, much as they would have varied 

 in the wild state, if such favourable opportunity had there occurred. Continued 

 cultivation under artificial selection would of course force some of these results 

 to an extreme never reached in nature, giving to long-cultivated varieties a cha- 

 racter of their own. Yet they may not deviate more widely from the wild type 

 than do some of the wild varieties of many plants of wide geographical range. 

 Moreover, Professor Gray maintained that there occur in nature the same kinds 

 of variation as those to which we owe our improved fruits, &c. ; that such origi- 

 nate not rarely in nature, and develope to a certain extent, enough to show the 

 same cause operating in free as in controlled nature ; enough to have shown the 

 cultivator what he should take in hand ; enough to render it likely that most of 

 our cultivated species of fruit began their career of improvement before man 

 took them in hand. Instances of such variations in the wild state were adduced 

 from our hawthorns, especially Crataegus tomentosu, from our Wild Red Plum, 

 Wild Cherries, and especially from our Wild Grapes and Hickories. 



3. The view taken by Mr. Lowell, and especially by Professor Bowen, fliat the 

 indefinitely long periods of time which the theory acquired and assumed was 

 practically equivalent to infinity, and therefore rendered the theory "com- 

 pletely metaphysical in character," Professor Gray animadverted upon, mainly 

 to remark that the theory in question would generally be regarded as too 

 materialistic and physical, rather than too metaphysical in character; and that 

 a fortiori, physical geology and physical astronomy would on |the principle be 

 metaphysical sciences. 



4. Exceptions were taken against the assumption of such a wide distinction, or 

 of any sharply drawn distinction at their confines, between the animal and the 

 vegetable kingdoms, and especially against the view that instinct sharply defines 

 the animal kingdom from the vegetable kingdom on the one hand, and from man 

 on the other, and which denies to the higher brutes intelligence, and to man 

 instinct. 



5. Also, against the view that the psychical endowments of the brute animals, 

 whether instinct or other, are invariable and unimproveable ; and a variety of 

 instances were adduced, as recorded in the works of Pritchard and of Isidore St. 

 Hilaire, as well as some from personal observation, in which acquired habitudes 

 or varied instincts were transmitted from the parents to their offspring. That 

 such acquirements, once inherited, would be likely to continue heritable, was 

 argued to be the natural consequence of the general law of inheritance, the most 

 fundamental law in physiology ; that it is actually so, Professor Gray insisted 

 was well known to every breeder of domestic animals. 



6. For decisive instances of the perpetuity by descent or fixity, under inter- 

 breeding, of altered structure, Professor Gray adduced Manx cats and Dorking 

 fowls ; and he alluded to well-known cases of six-digited people, and the like, 

 transmitting the peculiarity to more than half of their ehildron, and even grand- 

 children ; showing that the salient peculiarity tended to be more transmissible 

 than the normal state at the outset ; so that, by breeding in and in, it was likely 

 that hexadacbyles could soon be made to come as true to the breed as Dorkings. 



7. As to the charge that the theory in question denies permanence of type, 

 Professor Gray remarked that, on the contrary, the theory not only admitted 

 persistence of type, as the term i3 understood by all naturalists, but was actually 

 built upon this admitted fact as one of its main foundations ; that, indeed, one of 

 the prominent advantages of this very theory was, that it accounted for this long 

 persistence of type, which upon every other theory remained scientifically unac- 

 counted for. 



8. Finally, as to the charge that the hypothesis in question repudiated design 

 or purpose in nature and the whole doctrine of final causes, Professor Gray 

 urged :— 1. That to maintain that a theory of the derivation of one species or 

 sort of animal from another through secondary causes and natural agencies nega- 

 tived design, seemed to concede that whatever in nature is accomplished through 

 secondary causes is so much removed from the sphere of design, or that only 

 that which is supernatural can be regarded or shown to be designed ; — which no 

 theist can admit. 2. That the establishment of this particular theory by scien- 

 tific evidence would leave the doctrines of final cause, utility, special design, or 

 whatever other teleological view, just where they were before its promulgation, 







