A Discussion on the Significance of Muscular 

 Anomalies. 



By 

 Richard J. Anderson. 



An interesting discussion on Anatomical variations took place at 

 the British Medical Association Meeting in Edinburgh last Autumn. 

 The following is a Summarized report. 



The discussion was opened by Professor D. J. Cunningham who 

 suggested the division of varieties into Retrospective and Prospective. 

 Simple ontogenetic arrests and Atavism or Progonism belong to the 

 retrospective group. Examples are Ectopia vesicae and imperforate 

 anus, both are the result of arrested development. The occipital lobe 

 of the Primate Brain, which appears at the 3 — 4 month, raises the 

 Quadrupedal to the Primate variety. The arrest of this lobe has been 

 noted in Microcephalic idiots. Milne- Marshall has said that develop- 

 ment presents a record of race history, in which entire chapters are 

 lost, many pages misplaced, and some so blurred as to be illegible. 

 The tissues after such an arrest may be said to be crystallized. The 

 phase produced is not necessarily connected with the original stem 

 form. Atavism implies the reproduction of certain ancestral traits 

 which are omitted in the ordinary course of development, or implies 

 that those which are blurred should become again distinct. Ape-like 

 convolutions have been noted in the brain of a Microcephalic idiot. 

 Some of these convolutions are characteristic of the lower, and some 

 of the liigher, forms of Ape; so that the convolutions would appear 

 to have been forced into a composite mould; limited and independent 

 formative energy of the individual type was scarcely the factor in 



