126 



MAMMALIA. 



the nulimental animal is really the movement of an 

 organised being, however simple its organisation may 

 be ; and we might perhaps inter this from the fact of 

 there being no new animal originated, without an act 

 of union on the part of animals already existent. 

 While the rudimental animal is still an extenseless 

 thing, or in that state in which it has been called the 

 punctum saliens, or starting point, it consists of a con- 

 taining membrane and contained fluid, which recipro- 

 cally act and react upon each other as the first motions 

 of life which it is possible for us to observe : but even 

 in this state of the mammalia we have no trace of 

 those inferior organisations, through which it is cus- 

 tomary with some theorists to suppose that an animal 

 must pass, before it is developed up to the dignity of 

 the mammalia ; for this punctum saliens, at the time 

 of its first and feeblest rudimental flutter, is not only 

 an animal but a vertebrated animal ; and not only 

 vertebrated, but clearly and specifically mammalia, 

 and not another class. We cannot speak with so 

 much precision as to how the case stands with the 

 marsupial animals, because they have not been sub- 

 jected to the same careful examination ; but there is 

 not the slightest doubt but that all the true mammalia 

 are as characteristic in the first movement of their ru- 

 diment, and even in their rudiment before it begins to 

 move at all, as they are in the full development of 

 their strength and vigour. On this, as on all other 

 branches of animal physiology, more attention has 

 been paid to man than to any other order of mamma- 

 lia ; but in so far as they have been examined, the 

 law regarding them appears to be uniform. They are 

 vertebrated animals ; and the spinal column is the first 

 distinctly traceable part of their early organisation. 

 It is impossible to say that this is merely the medul- 

 lary substance of the spine ; for the probability is, 

 that it contains the rudimental bone, though both the 

 bone and its contents are yet nearly iw a fluid state. 

 It is remarkable, however, and calculated to prevent 

 us from doing wrong, if it does not carry us far in the 

 right way, that the spine is developed before the head; 

 for at its first rudimental appearance, the head, which 

 afterwards increases so much in proportion to the 

 spine, is not perceptibly thicker ; and altogether the 

 development of the spinal column precedes that of 

 the brain, properly so called, though by the time of 

 regular parturition the development of the head has 

 got greatly the advantage. 



The only inference which we can with safety draw 

 from this is, that the different organs are developed 

 and come to maturity in that order of succession in 

 which the animal requires them, which is saying little 

 more than that, both in the young and the mature 

 state, the adaptation of the animal to the circum- 

 stances in which it is placed, is always the best that 

 we can suppose. 



There is evidently an intimate connexion between 

 the early developments of certain parts as compared 

 with others, and the influence which those parts have 

 upon the general organisation of the body ; and per- 

 haps there are none which are in this respect more 

 characteristic or more important than those which 

 determine the specific part that the individual is in 

 future to bear in that most important of all the merely 

 animal functions, the preservation of its race, notwith- 

 standing the successive deaths of generations. 



The development (for we may safely use this word 

 in merely speaking of the actual fact of the growth 

 and expansion of an organ which we can trace, and 



do not copulate it with any other organ or separate 

 substantive power by which as a substantive exist- 

 ence, we suppose the organ to be developed) the 

 development of those parts of the body in which the 

 different functions of life display themselves, varies 

 greatly in the different order and genera of the mam- 

 malia. Generally speaking, that part of the organi- 

 sation which carries on what are sometimes termed 

 the vital functions, or those of nutrition, circulation, 

 and respiration, is the first to be perfected ; and we 

 have at least an apparent reason for this in their 

 necessity to the development of the rest. The organs 

 of locomotion, and of those other motions which are 

 usually called voluntary, or which the animal appears 

 to have controul over in suspending or continuing at 

 its pleasure (at least within certain limits), vary per- 

 haps more in the degree of their development at the 

 time of birth than any of the others. This might be 

 expected to vary in proportion to the nature of the 

 food of the animal, and the degree of ease with which 

 this food can be reached and taken possession of. 

 Thus a grazing animal which nips the tender leaves 

 of the grassy sward that supports it, can find its food 

 at a very early age, because the finding of such food 

 requires comparatively little labour or strength, or 

 what we call sagacity. An animal, on the other 

 hand, whose food requires greater exertion and effortt, 

 and has to be lain in wait for, or hunted down, or 

 taken by force in any way, and against resistance, 

 requires a greater degree of development before it is 

 able to depend on its own resources. We accord- 

 ingly find that such animals are fed as well as suckled 

 by their parents, and that in the young state they are 

 gentle and playful, and do not acquire their pre- 

 datory dispositions until the weapons, and the mus- 

 cular structure necessary for the working of those 

 weapons, have acquired the proper tone. 



There are differences in different species, for which 

 the physiological causes cannot perhaps be assigned 

 in a manner altogether satisfactory. But still it is a 

 general law, the deviations from which appear to be 

 perfectly explainable in so far as we know the facts, 

 that the length of time requisite for bringing the 

 animal to perfect maturity, bears a pretty constant 

 proportion to the resources which the full grown 

 animal is to possess, and the necessity which it has 

 for those resources. The human race furnish perhaps 

 the most remarkable instance of this. Human beings 

 are longer in arriving at the full development and 

 exercise of their bodily powers than any other ani- 

 mals, even though the lives of those animals are of 

 longer duration than the life of man ; and when in 

 addition to the bodily powers we take the mental 

 sagacity, we find that this goes on increasing, 

 even after the decay of the others is far advanced, 

 which, by the way, is a strong proof that those 

 powers have quite a different origin and depend 

 on a different agency from the mere powers of the 

 body. In ihis last respect we cannot find an exactly 

 parallel case in the rest of creation, because there 

 is no mind there ; and in our virtual analysis of 

 human nature, it is difficult for us in all cases to sepa- 

 rate the mental portion from the bodily ; but in as 

 fur as this can be done, we have the analogy con- 

 tinued in man, who, as being the animal of most 

 varied resources, viewing him merely as an animal, is 

 also the one of most tardy development. The same 

 holds good in even the two sexes of the human race. 

 As society is constructed and conducted in all 



