Nov. 19, 1885J 



NA TURE 



65 



Having now illustrated some principles of variability, and 

 given some idea of the extent to which it may go, under our 

 ov\n observation, we must deal with the question before us by 

 way of hypothesis. 



Let us suppose a primitive or typical Bee among the honey- 

 seeking insects of early days. She is necessarily a creature 

 having such attributes as are common to all species of bees which 

 are her offspring, but in many respects she is very unlike our 

 Hive Bee of to-day. We see her at a time when this typical 

 species has already learned the wonderful lesson of thrift. She 

 stores honey in times of plenty to provide for times of want. 

 She is feeding her offspring from her stores. As the keen com- 

 petition of life goes on, she must provide for the wants of her 

 offspring for an ever-increasing period, and, as her powers in 

 this respect are taxed to the utmost, her powers of reproduction 

 are of necessity diminished ; she produces some imperfect eggs, 

 and she produces fewer eggs. Still, the vast majority of her off- 

 spring perish, eitlier for lack of sufficient food or as prey to 

 natural enemies before their power of self-defence are sufficiently 

 developed for successful flight or resistance. 



It is quite reasonable to suppose that the bee has been sub- 

 jected to such vicissitudes as these. The extraordinary differ- 

 ences in the sizes of the various living species of bees would 

 indicate the truth of the theory of insufficient food as far as we 

 have yet followed it. If we have a species of bee only one- 

 eightli of an inch in length while some others are an inch and a 

 quaiter in length and stout in proportion, it will take one thous- 

 and (1000) of these Lilliputian bees to weigh as much as a 

 single specimen of one of these largest species. Is it not most 

 reasonable to suppose that this tremendous variation in size is 

 chiefly due to the matter of food supply, as is the well-known 

 fact in the very large variation we can thus make in the size of an 

 individual fish? 



Now \\ hen the food supply is so very scant that the size of the 

 offspring is necessarily much dwarfed, evidently the weakest 

 will die in the process of rearing ; evidently also the mother-bee 

 whose reproductive powers are the weakest as to the number of 

 offspring, and whose maternal in-tincts are the strongest, that is 

 to say, the one that lays the fewest eggs and takes the best care 

 of her young, will best succeed. 



If any broods of young perish altogether from famine, it will 

 be those that are so numerous as entirely to overtax the powers 

 of the mother-bee in feeding them. Thus we gradually approach 

 a time when the care of the mother-bee extends to a period in 

 the life of the offspring when they appreciate and respond to 

 her affection. The offspring are still numerous and the struggle 

 for existence is severe. The food supply is sufficient to bring 

 the young to that point in existence when they are capable of 

 applying with some prospect of success the instinct, that is to 

 say, the congenital knowledge, inherited from the mother. And 

 as the mother-bee continues after this period to help them in 

 their struggle for existence, they see and understand her assist- 

 ance, and they necessarily respond to her affection. Here is 

 definitely established filial love, in response to maternal affection, 

 and it is necessary that this filial love should be established in 

 strength even in this little insect before it is possible that the 

 specialization under consideration sliall commence. It must not 

 be supposed that the size of these tiny creatures renders them 

 incapable of this strong feeling — we must in this respect as in 

 others go by the evidence of our senses and the necessities of the 

 ease. Without strong aftection the whole life of these bees is 

 quite inexplicable, while with it their conduct is the natural out- 

 come of a certain amount of intelligence applied to certain 

 conditions of existence. 



Among all creatures nursed with a mother's care, filial love 

 grows stronger and stronger according to the capacity and cir- 

 cumstances of the offspring and the strength of that aftection 

 whicli calls it forth. But when the time for mating approaches 

 the young seek other relationships and so far as it is incompatible 

 with these does filial love decay. 



But what happens if the young are by nature incapacitated for 

 these other relationships ? 



Then filial love necessarily grows with the individual and 

 strengthens with her strength. 



The mating instinct may be almost or wholly lacking ; and, 

 if wholly lacking, then all of that part of the highly nervous 

 organization inherited from the mother tliat is devoted to the 

 affections will have no other outlet than in filial love. 



The common life around us, and man himself will perhaps 

 afford us some partial illustrations of this necessary law. The 



best illustration outside of the insect world is one of which the 

 facts may be easily ascertained by any person who will make the 

 inquiry. 



The breeding of mules is an important industry. The horse 

 and the ass are capable of strong affection, but their colts seldom 

 develope a filial love which has a controlling influence on their 

 adult life. 



But the mule, the hybrid between the male ass and the female 

 horse, except in very rare instances, is congenitally incapable of 

 reproducing its kind. It has more 01 less of the instinct for 

 mating, but it necessarily does not have the strong sexual passion 

 of a perfect equine animal. Its love for its mother however 

 amounts to a master passion ; it is not spasmodical, but it is 

 intense and it continues as long as there is an opportunity of 

 showing it. It is capable of transfer to another object and 

 those who breed mules in large numbers take a useful, instructive, 

 and amusing advantage of this fact. 



When the young mules are weaned, the mothers are with- 

 drawn from their company, and one, otherwise worthless old 

 mare is substituted for many mothers. The poor young things 

 turn to the good-natured old mare as to a very goddess ; while 

 she receives their worship with the equanimity of her sex, never 

 hinting in the mildest terms that it is an idolatry that should be 

 abated. As the dil.apidated goddess herself may be depended 

 upon for her staid qualities, it follows that her worshippers are 

 tliereby kept out of mischief. And the poor mule is not a 

 backslider, it is always a consistent worshipper. 



I liave stated that filial love is absolutely necessary to the 

 specialisation under consideration. It should be added that it 

 mu-t be intense in its character and capable of replacing to a 

 large extent the maternal instinct of the perfect creature. 



From the fact that insufficiency of food would aft'ect the 

 growth of all organs we deduce the further fact that it would 

 affect weak organs the most, giving those. not congenitally 

 perfect an irregular development. It follows also that if a very 

 young animal congenitally perfect, receives for a long period 

 only sufficient food to sustain life, the organs not vital will be 

 more or less dwarfed in their proportions, as compared to the 

 vital organs. 



For here the law of parsimony is absolute. The vital organs 

 must receive a certain supply, or the life perishes. The non- 

 vital organs make no such imperative demand, and they conse- 

 quently get less in proportion. And an organ that is entirely 

 useless to the life of the individual, would under such circum- 

 stances receive no nourishment whatever ; excepting only as it 

 is correlated to the organs that are useful or vital. The repro- 

 ductive organs of the young of all species are entirely useless to 

 the life of the individual ; their powers are latent, and, excepting 

 as they are correlated to other organs, they make no demand for 

 nourishment. Starvation must therefore dwarf the reproductive 

 organs of very young individuals, in proportion to those which 

 are very important, or absolutely necessary to life. In plants 

 this fact is constantly shown all around us and our maize is a 

 striking example. 



The reproductive powers of swine are very great. But a 

 young pig that is half-starved will not only have its reproductive 

 powers very much retarded in their growth, it will have them 

 diminished in their ultimate strength. This is a matter in which 

 general observation furnishes the proof. I have not asked fish- 

 culturists the question but I am absolutely certain that, other 

 things being equal, the number of fish-eggs will depend upon 

 the size and thrift of the individual, and these, other things 

 being equal, depend upon the question of food. 



It is easy to imagine a possible case among the vertebrates or 

 even the mammals in which a perfectly normal organism by long 

 continued insufficiency of food, is allowed a slow development of 

 those organs that are absolutely necessary for its life, and of the 

 others most nearly correlated to these, while the organs of re- 

 production, in the incipient or undeveloped stage in which they 

 were when starvation commenced, still remain till they become 

 fixed and immutable, notwithstanding any abundance of food 

 that may be given at a later period of life. 



Let us now go back to the variability of eggs as shown by our 

 hundred chicks or the variability of seeds as shown by our ears 

 of corn. This variability is variability of the germs, and this is 

 congenital variability. This variability as shown in the hundred 

 chicks gives us from three to six pounds for their adult weight 

 and they all differ in colour, form, or both. 



We take no account at present of the fact that our primitive 

 bee as shown by her offspring of to-day was far more variable 



