410 THE BLOOD, BY ALEXANDER ROLLETT. 



protoplasm, in which metamorphosis the essential characters 

 of the latter are lost, it is impossible to avoid expressing our 

 opposition to the theory of Hensen. In fact, the forms which 

 led Hensen to the above-mentioned view are susceptible of 

 quite a different interpretation. 



Briicke,* who observed such forms to be produced by the 

 action of a two per cent, solution of boracic acid, considers that 

 there is a porous structure composed of a non-contractile, very 

 soft, colourless, perfectly transparent substance, which he further 

 represents as the body of an animal, whose central part 

 forms the nucleus of a nucleated corpuscle, and is free from 

 haemoglobin, whilst the remaining portion of the mass contains 

 the whole of the hsemogoblin. Briicke considers that this latter 

 portion accurately fills the intermediate spaces of the porous 

 mass, and thus in combination with the parts free from pigment 

 makes one continuous whole. To the colourless porous sub- 

 stance he has applied the term " oekoid" whilst he calls the 

 contained substance the " zooid ; " and he is of opinion that 

 the retraction of the zooid either completely or partially from 

 the oekoidexplains the formation of the above-mentioned forms. 



Strieker^ agrees with Briicke in considering the oekoid to be 

 the part enclosing the colouring matter, and as that which 

 under certain conditions can retract towards the nucleus. He 

 terms it the " body," at the same time attributing a greater 

 amount of independence to the nucleus, and drawing attention 

 to the analogy between the blood corpuscles of Amphibia and 

 Mammals. 



The question now arises, are the red blood corpuscles con- 

 tractile as a whole, or is that part only contractile which is 

 called the zooid by Briicke, or the body by Strieker ? 



KlebsJ regarded the blood corpuscles of Mammals as contrac- 

 tile bodies, in consequence of his observations on the influence 

 of temperature, though these have since been opposed by Max 

 Schultze. The mulberry form he considered to correspond to 

 the mobile condition, the curved-disk form to the quiescent 



* Wiener BericUe, Band Ivi., p. 79. 



t Pfliiger's Archivfilr Physiologic, 1868, p. 591. 



I Centralblatt fur die medicin. Wissenschaften, 1863, p. 851. 



