Miscellaneous, 



568 



[June, 1909. 



gain most benefit in attending the 

 Agricultural College. In too many- 

 instances an owner of a small area 

 contents himself with letting his land to 

 a cultivator, often of inferior mental 

 capacity, and with receiving a share of 

 the produce at harvest ; whereas, if he 

 used his superior brain power in direct- 

 ing his labourers, he would very pro- 

 bably obtain a larger return from the 

 land. 



HEREDITY. 



By R. H. Lock. 



The children of men are like their 

 parents ; so are the children of animals 

 and plants. The time is not so very 

 remote when this was the sole definition 

 which could be given to the term here- 

 dity ; and information as to the nature 

 of this mysterious process was neither 

 sought nor found. 



Simple as the above statement may 

 seem, there is yet a valuable truth 

 embodied in it. Our ancestors were 

 endowed with powers of belief which 

 enabled them to accept as true the 

 most exaggerated assertions with regard 

 to unlikeness between parents and their 

 children. Among other remarkable 

 manifestations of faith they believed 

 that an animal might be the offspring 

 of a plant or vice versa, as in the case of 

 the celebrated barnacle goose. This 

 was a tree described and illustrated by a 

 famous savant of the Renaissance. The 

 fruits of the tree were barnacles, and 

 when ripe they opened and from each a 

 young bird emerged. The tree grew by 

 the margin of the sea, greatly to the 

 convenience of the geese, which fell 

 immediately into the water and swam 

 merrily away. 



Such a method of generation, if it 

 were actually to occur, would offer a 

 notable exception to the ordinary course 

 of heredity. Every rule has its excep- 

 tions, however, and it does not become 

 an honestly inquiring mind to deny the 

 possibility of even so remarkable an 

 ocounence as the birth of the barnacle 

 goose. Still anyone with a competent 

 knowledge of the comparative structures 

 of a goose, a tree, and a barnacle would 

 require, like Huxley, considerable evi- 

 dence before accepting the statement 

 that a bird actually came into being 

 in this way. The actual amount of 

 evidence which would be required is a 

 little difficult to estimate. No sane man 

 would nowadays accept the evidence of 

 his own eyes in such a case ; nor would 

 the testimony of twelve good men and 

 true approach the required standard of 

 verification. 



A universal belief, however exag- 

 gerated, has very often some grain of 

 trnth concealed in it, and we may seek 

 the kernel of these extraordinary stories 

 in the fact that the children, whether of 

 men or of plants, are never exactly like 

 their parents. In some cases indeed 

 they are very different, though usually 

 partaking of the racial or specific type 

 to which the parent belongs. 



The fact that a man has two separate 

 parents who are not identical effectually 

 disposes of any possibility of his exactly 

 resembling both of them. He might 

 indeed exactly resemble his father, but 

 it is a matter of common experience 

 that fathers and sons are always distin- 

 guishable. Most people on the other 

 hand show some points of resemblance 

 to both their parents. A child may 

 have its mother's eyes, and may take 

 after its father in the colour or texture 

 of its hair, whilst its nose may be the 

 very image of that to be seen in a family 

 portrait of its great-grandfather. If we 

 reflect upon the details of any particular 

 case, we shall very soon realise how 

 great a number of separate points go to 

 make up the complete hereditary endow- 

 ment of the individual. 



When we thus remember the great 

 number of separate features of resem- 

 blance to one parent or the other which 

 may be exhibited in any particular ease, 

 we see at once the great inconvenience 

 of treating individual people as units in 

 heredity. But it is only quite recently 

 thit anyone has ventured to adopt a 

 different method. The new method 

 consists in regarding the individual 

 animal or plant as being built up of a 

 number of separate factors, comparable 

 with the different kinds of stones with 

 which a house may be constructed. 

 These factors correspond in a general 

 way with the various features and 

 characteristics of the creature, and they 

 are inherited quite independently of 

 one another. 



The fust point, then, which is to be 

 emphasised in any account of modern 

 ideas about heredity is that which con- 

 cerns the existence of unit characters. 

 It is no mere metaphor when we speak 

 of the separate attributes of an organism. 

 But it is quite a recent discovery that 

 we can in effect take an animal or plant 

 to pieces and deal separately with the 

 inheritance of its separate parts. It is 

 not, however, separate limbs or organs 

 which are separately inherited so much 

 as certain definite attributes or charac- 

 teristics of these. Thus to take an ex- 

 ample, in the case of the domestic guinea- 

 pig, a kind of animal in which heredity 

 has ahvady been some >vhat fully studied, 

 the sort of characters which can be 



