OF DEVELOPMENT. 29 



bated by the animal heat developed by the maternal 

 organism. 



45. Of development. At first, however, in all 

 cases the minute particle of simple structureless bio- 

 plasm ( 11), out of which a complex organism is 

 evolved, gets its nourishment direct from the matter 

 which surrounds it, whether this is enclosed with 

 it from the first in a firm shell or supplied to it as 

 required from the blood of the mother. The fit and 

 proper substances are selected by the living matter 

 which moves towards them ( 37), takes them into 

 itself, and converts these into more living matter like 

 itself. Thus the primary living mass, from which 

 springs every succeeding bioplast that takes part in 

 the formation of the entire being, increases in size. It 

 divides into two or more, and these grow and divide 

 and subdivide until multitudes result. But as the 

 collection of bioplasts becomes larger by subdivision 

 and growth, it is obvious that the component bio- 

 plasts must be separated from the nutrient food by 

 very unequal distances. Without some special pro- 

 vision this would involve unequal nutrition. The 

 bioplasts upon the outer part or surface being in 

 actual contact with the food, would grow quickly, 

 whilst those towards the centre of the mass would 

 increase very slowly, and would cease to grow at all 

 in consequence of little or no nutrient material reach- 

 ing them. They would be starved and die. Such a 

 state of irregular growth does actually occur in the 

 case of certain morbid (cancerous) structures. Owing 

 to the circumstance of the irregular distribution of 

 nutriment, in one part growth is most rapid, while 

 in another situation the tissue actually dies from 

 starvation, and is often invaded and consumed by 

 new growth. In a very small space we may find in 

 such a texture, 1, young actively growing matter; 

 2, fully formed tissue; 3, decaying texture; and, 



