3IO LEO LOEB. 



(d) A 3 per cent, solution of formalin injected into lobsters or 

 spider-crabs has, if the blood is shed soon afterwards, a more or 

 less inhibiting effect on the coagulation, especially if the blood 

 is then also collected in a 3 per cent, formalin solution. 



Under such conditions it can be observed that all blood cor- 

 puscles of the lobster blood have granules, and that cells corre- 

 sponding to lymphocytes are normally not present in the blood 

 of the lobster. Their presence has lately been maintained. 1 



(i 1 ) The first coagulation of the blood can be prevented by 

 previously heating the animals ; the heat necessary to produce 

 this is different in different species. The blood of small Limuli 

 heated for 30-40 minutes up to 50-54 C. does not usually 

 coagulate after having been shed. Lobster or Libinia, heated to 

 4548 C. for 30 minutes loses its coagulability. Correspond- 

 ingly, lobsters and spider-crabs die at a lower temperature than 

 small Limuli. The cells usually leave the body after the animal 

 has been heated, in a round shape and later do not usually send 

 out pseudopodia, or do so to a less degree only. The spreading 

 out of blood corpuscles which usually takes place under normal 

 conditions does not take place after previous heating of the 

 animals, or if the animal has been injected with formalin. 



(f) Blood collected in the liver-pancreas juice does not coagu- 

 late to the same extent as ordinary blood. A large number of the 

 blood corpuscles are usually rapidly changed into granules and 

 many of them soon become entirely dissolved through the action 

 of the proteolytic ferment. 



(V) By previous injections of Liinitlns blood into turtles I have 

 not succeeded in obtaining either precipitins for Limnlus blood 

 or substances which inhibit the activity of its fibrin ferment. 



(/;) Limulns blood collected in gelatine solutions of different 

 concentration did not coagulate as readily as the blood collected 

 in water, gelatine having a decidedly inhibiting action. If the 

 solution of gelatine was very weak care had to be taken to avoid 

 the shaking of the blood, otherwise coagulation took place. The 

 blood corpuscles in gelatine were swollen and frequently formed 

 epithelial-like rows. 



1 A fuller description of the blood corpuscles of Limiilits is given in a previous 

 paper: Journal of Medical Research^ Vol. II., January, 1902. 



