TRANSACTIONS OF SECTION D, 67? 



two atle iiaturallsts who subscribe to the maternal impression doctrine, and it is 

 firmly held by many breeders and by not a few physicians. A writer in a recent 

 number of a quarterly,' which circulates widely amongst farmers and stock-keepers, 

 boldly asserts that the existence of impressions which affect progeny (more espe- 

 cially in colour) is a settled fact. This writer supports his case by referrinpf to a 

 highly successful breeder of polled Angus cattle, who considered it necessary to 

 surround his herd ' with a tight black fence in order to keep the females from 

 dropping red calves because they saw the red herds of his neighbours.' Reference 

 is also made by this writer to the belief, common in certain parts of England, that 

 whitewashed byres, regardless of the colour of the parents, produce light-coloured 

 calves ; that the colour of foals is often more influenced by the stable companion of 

 the dam than by her own colour or that of the sire ; and that even the colour of 

 birds varies with the immediate surroundings, fowls, e.g., however carefully 

 penned, hatching birds resembling in colour the hens they habitually see in a 

 neighbouring run. If maternal impressions thus influence the offspring they must 

 be one of the most effective causes of variation. During the last six years I have 

 bred many hundreds of animals, but the nearest approach to an instance of maternal 

 impressions was a dark pup with a white ring half round the neck, which suggested 

 the white metal collar sometimes worn by his sire. But similar rings round the 

 legs and tail rather discredited the view that the white neck-ring was in any way 

 related to the sire's nickel-plated collar. Telegony was sometimes said to be due to 

 maternal impressions. It was doubtless for this reason that I was urged some 

 years ago to carefully prevent the mares used in my experiments from seeing too 

 much of the zebras. But though numerous foals have been bred from mares 

 stabled with zebras or grazing with richly striped zebra hybrids, not a particle of 

 evidence have I found in support of the maternal impression doctrine. The foals 

 have neither stripes nor upright manes, and do not even attempt to mock the 

 weird barking call of the zebra. Sheep and cattle, goats, rabbits, and guinea-pigs, 

 fowls and pigeons, have simply confirmed the results obtained with horses. This 

 being the case, grooms may very well omit following the practice (considered so 

 essential in Spain during the Middle Ages, and still often religiously observed in 

 England and America) of setting ' before the mares . . . the most goodly beasts ' 

 by way of hinting to them the kind of foals they are expected to produce. 



The Needs of the Organism as a Cause of Variation. 



No recent biologists are perhaps prepared to believe like Lamarck that the 

 wings of birds were developed by their remote ancestors making efforts to fly ; that 

 by stretching its toes the otter acquired webbed feet ; nor are they prepared to 

 find in our new mammal, the Ocapi, evidence in support of Lamarck's contention 

 that to meet new needs the giraffe by much stretching gradually lengthened his 

 neck. Yet it is difficult sometimes to see any real difference between the beliefs 

 of the new Lamarckians and the old. It is maintained, for example, ' that when a 

 certain functional activity produces a certain change in one generation it will pro- 

 duce it more easily the next,? that, e.g., flounders and their allies by constant eilorts 

 generation after generation have dragged the left eye to the right side, while by 

 similar efforts in the turbot and certain other flat fishes the right eye has been 

 shifted to the left side. It is not alleged by Neo -Lamarckians that globe fishes 

 resulted from round fishes blowing themselves out, or that flounders resulted from 

 round fishes generation after generation making efforts to flatten themselves. If 

 by germinal variation and selection flounders were evolved out of round fishes, 

 is it not straining at a gnat and swallowing a camel to refuse to admit that by 

 the same factors the left eye of the flounder has been transferred from the left to 

 the right side of the head ? In the flat fishes it is not difficult to imagine how by 

 variation and selection the eyes originally acquired the power of responding to 

 certain external stimuli. 



' ^ibby's Quarterly, Autumn Number, 1900, p. 163. 

 1901. Y Y 



