of the Bed Blood Corpuscle. 23 



rapidly dissolved out, and leaving the nucleus and cell wall more 

 distinctly visible. In one instance, a corpuscle which had become 

 quite decolorized attached itself to some little mass of granular 

 matter, so that it could be retained under observation while I set 

 up currents beneath the cover by tapping the latter with a mounted 

 needle. On changing the direction of these currents so as to 

 strike the disk upon various parts of its surface in succession, I 

 was enabled to satisfy myself conclusively that it possessed a 

 bladder-like cell wall, perfectly flexible (now that it was no longer 

 distended with hsemato-crystallin), and capable of being dimpled 

 in, as it were, by the force of the current impinging upon any side 

 until it applied itself accurately to the subjacent surface of the 

 nucleus, thus furnishing strong evidence against the doctrine of a 

 sponge-like stroma (or oikoid), as taught by Briicke and Strieker, 

 being a constituent of the red blood corpuscle. 



If water was allowed to flow in upon a specimen, whose disks 

 had undergone the curious crystallization above described, diluted 

 liquor sanguinis seemed to rapidly enter the corpuscles by endos- 

 mosis, and dissolved the contained crystals which generally assumed 

 a foliaceous appearance, such as we often see crystals of triple phos- 

 phate put on, when macerated in alkaline urine. As the haemato- 

 crystallin dissolved, the natural colour of the corpuscle was 

 restored ; its walls, if they had been previously propped out upon 

 the points of the crystals, reassumed their normal shape, and in 

 some instances these shortened or broken crystals were observed to 

 move freely in the cavity between the nucleus and the cell wall. 



Before attempting to make any deduction from the above experi- 

 ments upon the blood of the Menobranchus, it may not be amiss 

 to refer briefly to the views entertained by most German writers in 

 regard to the red blood corpuscle. According to EoUett, in Strieker's 

 ' Handbuch ' above referred to, p. 296, Hensen was led, from the 

 apparent retraction of the cell contents from the membrane as 

 seen in the blood corpuscles of reptiles, to ascribe to the red disks a 

 protoplasm which, accumulated especially around the nucleus and 

 over the inner surface of the envelope, was bound together by 

 deHcate radiating crossed threads, and in its interstices contained 

 the coloured liquid cell contents (gefarbte zellfliissigkeit) ; but in 

 the opinion of Kollett, this thing is untenable in view of the 

 knowledge we have lately obtained in regard to the properties of 

 protoplasm, from the researches of Max Schultze and Kiihne. 



Briicke, who has observed these appearances after the action of 

 a 2 per cent, boric acid solution, pictures to himself in explanation 

 thereof, in the first place, " a porous form element, consisting of a 

 motionless, very soft, colourless, and perfectly transparent sub- 

 stance ; further, he represents to himself the body of the corpuscle 

 as composed of a living organism, whose central portion forms the 



