000 



(i. II. HKKW AM» W. UK MOl.'ilAN. 



no lnr(?o oosinopliile (j^riuiules. Accoi-diiit^- to Cuenot (1), tlicy 

 on'ijinii.to in a " glando lynijilnitiquo " situated at the base of 

 the gills. 



One of us (DicWj 4) has shown in the case of Cardiuni 

 norvegicuin tliat when the corpuscles come in contact with 

 a rou'i'h foreign body, or with injured tissue, they possess the 

 power of agglutinating and forming a compact plasmodial 

 mass. Ill this way bleeding from a small wound is stopped. 

 When the edges of a. wound are covered with tliis mass of 

 agglutinated corpuscles/ protoplasmic strands are formed 

 across tlie wound, connecting the plasmodia; these strands 

 tliicken and contract and so approximate the edges of the 

 wound. So far as our observations go, there is no reason to 

 su])j)ose that the blood of Pecten maxim us differs in any 

 of these particulars from that of Cardium norvegicum. 



That Lamellibrancli blood-corpuscles are capable of a 

 phagocytic action towards degenerated cells has been shown 

 by De Bruyne (3) in the case of My tilus edu lis, Ostrea 

 edulis, Unio pictoruni, and Anodonta cygnaea. Sir 

 Kay Lankester (5 and 6) has shown that certain corpuscles of 

 Ostrea edulis have a pliagocytic action on diatoms and 

 minute green algfe, and it has been shown by Drew (4) that 

 the corpuscles of Cardium norvegicum have a phagocytic 

 action on bacteria, and are attracted towards extracts of dead 

 tissues. 



The Formation of Fibrous Tissue in the Site op the 

 Implantation of a Mass of Gill-Tissue. 



As bacteria are normally present on the gill-filaments, the 

 conditions when gill-tissue is implanted differ totally from 

 those obtaining when sterile agar is used. 



The implantation soon produces an intense inflammatory 

 reaction on the part of the animal. The blood-spaces in the 

 immediate neighbourhood of the implanted tissue become 

 distended and crowded with corpuscles, which escape from 

 the lacunar spaces and migrate towards the source of irrita- 



