2i8 THE OVUM. 



much organisms and tissues in their fully formed state may 

 vary as regards the character, properties, and composition 

 of the formed material, all were first in the condition of 

 clear, transparent, structureless, formless living matter. 



Every growing cell, and every cell capable of growth, con- 

 tains bioplasm in every stage of existence. Bioplasm is the 

 most important constituent of every elementary part. The 

 bioplasm makes the formed material, but the latter is power- 

 less to produce the former. The young cell seems to con- 

 sist almost entirely of this living material a fact well 

 observed in a specimen of cuticle from the young frog, 

 which may be contrasted with more advanced cuticle from 

 the same animal. In the mature cells only a small mass of 

 bioplasm (the nucleus of authors) remains. In the fully 

 formed fat cell there is so little bioplasm left, that it may be 

 easily overlooked. In disease, on the other hand, the 

 bioplasm may increase to three or four times its ordinary 

 amount, and in that case it becomes a very striking object. 

 In inflammation the bioplasm may increase to such an 

 extent as to destroy every particle of formed tissue which is 

 the seat of the change^; and in fever, the circulation may 

 be obstructed and death caused by the rapid multiplication 

 of particles of bioplasm. These may also grow and 

 multiply in the interstices of the tissues and organs, and 

 paralyse their action and cause death before sufficient time 

 has elapsed for the destruction of the tissue itself.* 



The ovum at an early period of its development is but 



a naked mass of bioplasm, without any cell-wall, but having 



a new centre or many new centres (known as germinal spots 



or nuclei) embedded in it. The mode of formation of 



* " Disease Germs," page 188. 



