594 



NATURE 



[October i8, 1900 



In the chapter on Lamarck a powerful argument is 

 derived from " adjustments to the life of other beings than 

 the ones which exhibit the adjustment," such as the 

 poison-fang or sting, which are valuable to the possessor 

 because of their effect on other species. The author 

 finds " the production of adaptations of this sort by the 

 inheritance of the beneficial effects of use, or in any way 

 except by selection, quite unthinkable." Henslow's 

 volume, "The Origin of Floral Structures through Insect 

 and other Agencies" (Internal. Scientific Series) does 

 not appear to be known to the author, although by a few 

 well-chosen examples he shows the futility of the sup- 

 posed origin which is therein suggested. 



"For all I know, the Lamarckian may claim that the 

 visits of insects have, in some way, modified the flower, 

 to its own good, by their mechanical action, by pulling 

 down this part, and by pushing up that, generation after 

 generation, until they have caused adaptive modification 

 in the flower. I do not know how much his ingenuity 

 may be able to make out of this hypothesis ; but no one 

 can believe that the hooks and spines, which are so 

 obviously adapted for distributing burrs and seeds, by 

 fastening them to the fur of passing mammals, have been 

 produced by the inheritance of the effects of this sort 

 of mechanical contact ; for these structures do not come 

 into use until they are dead ; and, most assuredly, dead 

 things cannot transmit 'acquired characters' to their 

 descendants. When a drop of rain or dew falls on the 

 dead, dry, twisted glume of the animated oat {Avena 

 sterilis), it untwists in such a way as to push like the leg 

 of a grasshoper, and, raising the seed, to send it off with 

 a jump. After the seed has fallen, this process is repeated 

 again and again, until the heavy end, where the seed is 

 placed, falls at last into some roughness in the ground, 

 when the glumes begin to kick and to struggle, and, 

 catching in the grass and roots, or on the rough ground, 

 to push the seed down and to plant it. The seed is 

 alive, but the glumes are dead and dry, and as com- 

 pletely out of the line of descent to future generations as 

 the dead leaves which drop from the tree." 



This quotation illustrates the very effective manner in 

 which the Lamarckian principle is dealt with. In certain 

 striking cases it is shown to be obvious that the hypo- 

 thesis of Lamarck cannot supply an explanation, while 

 selection offers a probable solution. At first sight these 

 examples may appear to be exceptional and rare, but 

 the author shows us that 



" all the adaptations of nature are of this sort. In all 

 cases, the structure, habits, instincts and faculties of 

 living things, from the upward growth of the plumule of 

 the sprouting seed to the moral sense of man, are 

 primarily for the good of other beings than the ones 

 which manifest them." 



In support of this conclusion, the evidence of "the 

 insignificance of the individual, as compared with the 

 welfare of the species " is marshalled and illustrated in a 

 peculiarly convincing and striking manner. Of all the 

 examples, the most wonderful is certainly that of the 

 queen-bee in her relation to the other members of the 

 royal family and to the hive. A hive requires a queen, 

 but would be disorganised by the presence of more than 

 one queen at the same time. Until the queen-mother 

 has led out a swarm, the workers will not permit a young 

 queen, although mature, to leave her cell. In order to 

 preserve her from the reigning queen, she is walled up 

 with layers of wax and fed through a small opening. 

 NO. 1616, VOL. 62] 



When swarming has occurred, a young queen is allowed 

 to escape : she in her turn is impelled to kill the rest of 

 the royal brood, but is prevented by the workers. Later 

 on in the season, however, when it is no longer possible 

 to swarm, the attitude of the workers entirely changes, 

 and they now " incite her to destroy her rivals." And 

 here we meet with a most wonderful adaptation. It is 

 obvious that any royal larva may, under certain circum- 

 stances, benefit the hive by producing a reigning queen, 

 or, on the other hand, under different circumstances, 

 may be killed in order to prevent a danger to the com- 

 munity. The instincts of the royal larva are such that it 

 prepares beforehand for the latter alternative, and facili- 

 tates its own murder without inconvenience or danger to 

 the queen, by spinning an incomplete cocoon which ex- 

 poses the soft abdomen to the sting. Darwin pointed 

 out in the "Origin of Species" that the social Hymen- 

 optera afford the most complete evidence of instincts 

 which cannot be due to use-inheritance inasmuch as 

 they are exhibited by the sterile workers, the offspring of 

 drones and queens with quite different instincts. Brooks 

 has used the same example with great effect to empha- 

 sise " the supreme importance of the species, and the 

 relative insignificance of the individual." Darwin's con- 

 clusion is also put with remarkable force on p. 95. This 

 most interesting and convincing chapter concludes as 

 follows : 



" Some may ask whether it may not be possible that 

 while natural selection is the chief factor in the origin of 

 species, there may still be a residuum to be accounted for 

 by the ' inheritance of acquired characters.' For all I 

 know this may be not only possible, but actually the 

 case. I have never felt the slightest interest in a priori 

 demonstrations of the impossibility of this sort of in- 

 heritance ; and for all I know to the contrary, proof of 

 its occurrence may be found at any time, although I 

 know no good evidence of its occurrence. I had satisfied 

 myself, long before the recent revival of interest in the 

 matter, that whether it be a real factor or not, the so- 

 called Lamarckian factor has little value as a contribu- 

 tion to the solution of the problem of the origin of 

 species ; and renewed study has strengthened this 

 conviction." 



It must be remembered, on the other hand, that such 

 inheritance would require an inconceivably elaborate 

 mechanism, which can hardly have arisen and been 

 sustained in order to account for a factor which is of 

 little value in evolution. 



" Migration in its bearing on Lamarckism " is the title 

 of the succeeding lecture. The same subject was treated 

 of in one of the most fascinating of Wallace's classical 

 essays upon natural selection. It is interesting to com- 

 pare the two, and to recognise how very greatly the 

 interpretation of this difficult problem has been 

 elucidated by the younger zoologist. Wallace dwells 

 upon the lines of bird migration in their relation to past 

 geographical change, and to the special need for insect 

 food during the breeding season. Brooks treats the 

 problem as a part of the wide principle of the subordin- 

 ation of the individual to the welfare of the species ; he 

 doubts the dependence on geological change and the 

 great importance of food, and makes the illuminating 

 suggestion that security from the enemies of eggs and 

 young is the controlling factor alike of bird and fish 



