EXPERIMENT STATION RECORD. 



Vol. XIII. No. 3. 



The address of J. Cossar Ewart, M. I)., F. R, S., at the recent meet- 

 ing- of the British Association at Glasgow will be of interest to persons 

 who appreciate the frail foundation upon which our knowledge of the 

 science of l)reedincr animals rests and the desirability of systematic 

 experiments directed along that line. Dr. Ewart, who is professor of 

 natural history in the University of Edinburgh, is well known for his 

 investigations in this line, which have extended over a number of 

 years, although the results have been published only in part in zoo- 

 logical and veterinary journals. A number of his papers on the sub- 

 ject of telegon}" and reversion and the results of breeding zebra hybrids 

 were published in book form in 1899 under the title of The Penjxuik 

 Experiments, named for the place where these experiments have been 

 conducted. In that volume he presented the views held by biologists, 

 breeders, and others interested in the question of telegony or "germ 

 infection," a tenu which he defined as a convenient explanation of 

 many of the obscure phenomena which come under the notice of 

 breeders and fanciers. He there outlined a series of experiments 

 which might be undertaken on that subject and signified his desire to 

 correspond with anyone interested in undertaking some of these 

 experiments. 



In the meantime his own experiments have been continued. This 

 year, as president of the zoological section of the British Association, 

 he delivered the opening address, taking for his subject "The experi- 

 mental stud}' of variation." In this he reviewed the theories of vari- 

 ation and cited man}^ experiments with different kinds of animals. 

 He gave special attention to the subject of the cause of variation — the 

 possible effect of age, ripeness of the germ cells, condition of the 

 soma, change of habitat, environment and use-inhpritanco, and teleg- 

 ony — and discussed the effects of intercrossing and interbreeding on 

 variation and the swamping effect of intercrossing on new varieties. 

 In regard to the subject of telegony, after carefully considering all 

 the more striking supposed cases of " infection," Dr. Ewart stated 

 very positively that "there is no satisfactory evidence that there has 

 ever been, either in the human family or amongst domestic animals, a 

 single instance of infection." He indicates that the true cause of 



201 



