:;4ii THE CLASSICAL TRADITION 



Two movements seem significant in the morphology of 

 the last decade or so of the iQth century first, the experi- 

 mental study of form, and second, the criticism of the 

 concepts or prejudices of evolutionary morphology. 



The period was characterised also by the great interest 

 taken in cytology, following upon the pioneer work of 

 Hertwig, van Bcneden and others on the behaviour of 

 the nuclei in fertilisation and maturation. 1 This line of 

 work gained added importance in connection with contem- 

 porary research and speculation on the nature of hereditary 

 transmission, and it has in quite recent years received an 

 additional stimulus from the re-discovery of Mendelian 

 inheritance. Its importance, however, seems to lie rather in 

 its possible relation to the problems of heredity than in any 

 meaning it may have for the problems of form. More 

 significant is the revolt against the cell-theory started by 

 Sedgwick- and Whitman, 3 on the ground that the organism is 

 something more than an aggregation of discrete, self-centred 

 cells. 



The experimental work on the causes of the production 

 and restoration of form infused new life into morphology. It 

 opened men's eyes to the fact that the developing organism is 

 very much a living, active, responsive thing, quite capable of 

 relinquishing at need the beaten track of normal development 

 which its ancestors have followed for countless generations, 

 in order to meet emergencies with an immediate and pur- 

 posive reaction. It was cases of this kind, cases of active 

 regulation in development and regeneration, that led men 

 like G. Wolff and H. Driesch to cast off the bonds of dogmatic 

 Darwinism and declare boldly for vitalism and teleology. 



There was the famous case of the regeneration of the 

 lens in Amphibia from the edge of the iris an entirely 

 novel mode of origin, not occurring in ontogeny. The fact 

 seems to have been discovered first by Colucci in 1891, and 

 independently by G. Wolff in 1^95.' The experiment was 

 later repeated and confirmed by Fischel and other workers. 



1 Sec V.. B. Wilson's masterly book, The Cell in Development umf 

 Inheritance, New York and London, lyoo. - Q.J.Af.S., xxvi., 1886. 



1 ll'ood's I loll I lio lexical Lectures for 1893. 

 4 Arch.f. Enf.-AIech., i., pp. 380-90, 1895. 



