448 PEOF. B. C. A.. WINDLE OlST TEEATOLOQ-ICAI; ETIDENCE 



Teratological Evidence as to the Heredity of Acquired Condi- 

 tions. By Beeteam C. a. Windle, M.A., M.D., Professor 

 of Anatomy in the Queen's College, Birmingham. (Com- 

 municated by E. B. PouLTON, M.A., E.E.S., E.L.S.) 



[Eead 7tli February, 1890.] 



The subject of congenital malformations is one which, strangely 

 enough, has met with but little notice amidst the mass of evi- 

 dence which has been brought forward, on one side or the other, 

 as to the transmissibility of acquired characters, a question which 

 has provoked, and is provoking, so much controversy. 



Yet it is certain that the consideration of the question from 

 its teratological aspect ought to be of some service, since, in the 

 first place, there are two groups undoubtedly amongst congenital 

 malformations, blastogenic and somatogenic, to use "Weismann's 

 terms, though it may not always be easy to assign a given defect 

 with certainty to either. And, again, it ought to be possible to 

 throw some light upon the difficult question of the origin, deve- 

 lopment, and fate of a variation, from the copious mass of lite- 

 rature which exists in relation to teratological subjects. It seems 

 probable that the reason why this field has been so little explored 

 in the present connection, is that the etiological side of teratology 

 has, up to the present, been so much neglected. Professor 

 Clelaud, who has done so much for the study of the subject in 

 this country, has very aptly remarked that teratology should 

 be defined as " pathological embryology." Before, however, 

 much practical informatioa can be gathered from the subject, it 

 is, above all things, necessary that its classification should be 

 arranged upon an etiological basis. The author just quoted 

 remarks in an essay on "Teratology, Speculative and Causal, 

 and the Classification of Abnormalities "* : — " If the advantage 

 whicli biological doctrine has hitherto derived from teratology has 

 not been great, the reason has lain, not in the barrenness of 

 the teratological field, but in the small amount of progress 

 made in determining the true nature of teratological pheno- 

 mena. Even after the old conception of lusm natures had been 

 thrown aside, the most imperfect notions continued to prevail 



* ' Memoirs and Memoranda in Anatomy,' vol. i. 1889. 



