BOOK REVIEWS 41 



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Book Reviews 



Modern Problems of Biology. Lectures delivered at the 

 University of Jena, Dec. 191 2. Charles Sedgwick Minot, pp. ix 



+ 124- 



Professor Minot was exchange professor when these six lectures 

 were delivered. Their titles are i. The New Cell Doctrine. 

 2. Cytomorphosis. 3. The Doctrine of Immortality. 4. The 

 Development of Death. 5. The Determination of Sex and 

 6. The Notion of Life. 



"The living substance is more important to biologists than its 

 tendency to form cells. Hence we consider the chief problem of 

 biology to be the investigation of the structure arid chemical 

 composition not of cells, but of the living substance." This is 

 the new cell doctrine. Cells pa,ss through a definite cycle of 

 changes first an embryonic condition, second differentiation, 

 third degeneration and finally death. This constitutes cytomor- 

 phosis. But certain cells never die. The reproductive cells 

 multiply, dividing to become new cells but the stream of their 

 protoplasm is continuous or immortal and this is the basis of 

 heredity. The rest of the cells multiply with rapidity in embryonic 

 life, pass through their successive stages, finally die. Thus rabbits 

 may grow as much as 18% per day just after birth. But this 

 rapidly drops so that within a month they are growing less than 

 four per cent per day. They are already ageing rapidly. Minot 

 believes that it is already proven that "sex rests on a physical 

 basis which we recognize by differences in the proportion of 

 chromatin in the cells of the male and female body." Finally he 

 concludes that while "life is bound to matter . . . there always 

 remains the possibility that consciousness cannot be explained 

 mechanistically, that it is neither a condition of protoplasm, nor 



