20 PROCEEDINGS OF TBE 



pulverized, and every statement of Bateson confirmed in the 

 sixteen years that have succeeded the publication of Spengel's 

 work. 



Dr. Gaskell calls the theory of " parallel development," by which 

 he means the theory of the independent origin of the great phyla 

 Arthropod.!, Mollusca, Vertebrata, &c. from simple forms, an 

 " unscientific and inconceivable suggestion."' Surely he has for- 

 gotten the ' Origin of Species.' 



Does he forget that Darwin felt the differences between these 

 phyla so strongly that he doubted their common origin, and seems 

 to have imagined that they might have originated independently 

 from primordial protoplasm. Does not Dr. Gaskell know that 

 those who give their lives to the study of Zoology have " parallel 

 development " or fan-like development forced on them at every 

 turn, in every section and sub-section of the Animal Kingdom. 

 That the air-breathing type of gastropod Mollusc, for instance, 

 must have originated at least half a dozen times and the snake- 

 like Vertebrate at least a dozen times each time in entire inde- 

 pendence of every other. And why unscientific ? If protoplasm 

 be fundamentally the same sort of thing at bottom, and if varia- 

 tions be due to definite changes in its chemical composition 

 produced directly or indirectly by changes in the environment, 

 should not like causes have like results ? 



Dr. Gaskell states that his theory strikes at the root of the 

 conception of parallel development. In this case I venture to 

 predict ttiat the root will prove to be more resistant than the axe 

 with which it is struck. 



Prof, E. H. SxAELiNG, F.R.S. (Visitor), followed and remarked : 

 I do not know how far an apology may be considered necessary 

 for the intervention of a physiologist in the discussion of a topic 

 which has hitherto been regarded as the special preserve of the 

 zoologist and comparative anatomist. I understand, however, that 

 the chief criticism of the theory, which has been so ably put before 

 us this evening, has had reference to the method by which the 

 problem is attacked, rather than to the facts in comparative 

 anatomy which have been discovered or collated by Dr. Gaskell. 

 On this point, namely, the principles which must guide any 

 research into the phylogeny of our race, a physiologist has as good 

 a right to be heard as has a comparative anatomist. In fact, it 

 was the author of the ' Origin of Species ' himself who introduced 

 physiological considerations into the theory of descent. Darwin 

 showed that the grouping of living beings made by zoologists had a 

 far deeper significance than mere resemblance of form, and were 

 really expressions of blood relationships among the members of 

 any group or between allied groups. He thus replaced a purely 

 conceptual anatomical grouping by an actual physiological kinship. 

 Since the varying degrees of divergence among different forms are 

 to be referred to the survival only of such individuals as are most 



