LIVING MATTER IN "PROTOPLASM." 37 



THE STRUCTURE OF THE BLOOD-CORPUSCLES OF THE OYSTER. 

 BY A. M. HURLBUTT.* 



If we break the shell of an entirely fresh oyster on its thinnest edge, a 

 small quantity of sea-water will ooze out. If we open the oyster by pulling 

 apart the two valves, around the injured oyster a large quantity of fluid 

 accumulates. This fluid contains the blood-corpuscles. First we oil the 

 edges of an extremely thin cover on one side, place a small drop of the 

 juice of the oyster upon a slide, and cover it with the covering-glass, the 

 greased edges looking toward the slide. We then have a specimen ready 

 for examination with the highest powers of the microscope. 



A power of about five hundred diameters will reveal numerous granules 

 floating in the fluid, in what has been termed molecular motion. These are 

 granules of fat, of pigment, and of broken protoplasm. In the fluid there 

 are swimming very often parasites, which I do not wish to consider at this 

 time. Furthermore, debris of the tissues of the oyster and epithelia are to be 

 seen, and lastly, numerous granular bodies, varying considerably in size 

 and form, and continually changing their shape or locality for at least two 

 hours. These are the blood-corpuscles of the oyster. Let us now put on a 

 lens with a magnifying power of twelve hundred. I used an immersion- 

 lens of Tolles, of Boston, and one of C. Verick, of Paris, both magnifying 

 about twelve hundred diameters with a short eye-piece, and both giving the 

 same results as to the structure of the protoplasmic bodies. 



We find globular bodies of the size of human re'd blood-corpuscles to be 

 considered as free nuclei, suspended in the fluid, and of which nuclei it is 

 impossible to say whether they exist as such in the live oyster, or are freed 

 by the injuring manipulation. Besides, spindle-shaped bodies are present, 

 not surpassing the nuclei in size. Lastly, protoplasmic bodies are visible, 

 varying in size from one and a half to seven or eight diameters of a human 

 red blood-corpuscle, partly roundish, partly elongated in one or several direc- 

 tions, or stellate, that is, provided with a number of delicate radiating off- 

 shoots . These protoplasmic bodies are in amoaboid motion, changing their 

 shape continuously by projecting flaps or elongated offshoots the so-called 

 pseudopodia on different parts of their peripheries, and withdrawing them 

 again. The changes of shape are not very lively about as slow in character 

 as we observe them on the amreba diffluens, or in colorless blood-cor- 

 puscles of the newt. At the same time locomotion of the protoplasmic bodies 

 takes place, so that a corpuscle might migrate through the field of vision of 

 the microscope within one hour. On the free nuclei I did not observe changes 

 of shape or locomotion. 



The blood-corpuscles are either devoid of a nucleus, or during the observa- 

 tion there may appear roundish bodies within the protoplasm, looking like 

 nuclei and disappearing again from our view. Other corpuscles from the very 

 beginning show from one to five or six nuclei. When nuclei are thus visible 

 at the beginning of the observation, they remain unchanged until the cor- 

 puscles in which they exist become motionless. In corpuscles in which no 

 constant nucleus can be made out, sometimes a nucleus becomes visible when 

 the corpuscle approaches the time of its death that is, when it becomes 

 motionless. 



Let us now watch a corpuscle in which a nucleus is plainly marked, and 



* New York Medical Journal, January, 1879. 



