76 



of the clotting of the urchins blood, describes the formation 

 of a clot in animals from which he removed a very small part 

 of their shell. After two hours he found the hole covered with 

 a crust just as a wound in mammals is covered up. All kinds 

 oF corpuscles were seen in these clots, the cells do not any 

 longer form amiboid pseudopodia, but are gradually transformed 

 into connective tissue („semblent deja en voie de transformation 

 conjonctive"). The same thing takes place in many other 

 species — the original experiments were conducted on Echinus 

 acutus. Lmk. — . It does not take place if the wound is too 

 large. Then the rims of the wound are closed, but the animal 

 dies, before it has been able to repair the damage. 



The biological importance of such protective clotting is very 

 evident, especially in the case of the Spatangidae, whose very 

 thin-walled alimentary tube seems to be especially liable to be 

 hurt by the sharp particles which are frequently taken in 

 with the natural food. Something of this nature may take place 

 in the case of injections of fluid into the coelomic cavity. 



In order to avoid all objections however, I injected the liquid 

 from very near the tip of the arm with a fairly long needle. 

 Close to the proximal side of the opening, I tied off the arm 

 with a cord. In that way it was not possible for any fluid to 

 escape. About one fifth of the total quantity was injected into 

 each arm and with some force so that one might suppose that 

 it was fairly well equally distributed through the whole perivis- 

 ceral liquid. 



At definite intervals a sample of one c.c. was drawn from 

 the coelomic fluid, with a syringe. In these samples the quantity 

 of sugar was determined by means of F o 1 i n and W u's micro- 

 sugar-method for blood filtrates. In this method the liquid to 

 be tested is boiled with an alkaline copper solution for 6 

 minutes. Phosphomolybdic-phosphotungstic acid is added to 

 dissolve the cuprous oxide. This is oxidised and the molybdic 

 reagent reduced with the production of a blue color, which is 

 then compared with a standard. This standard was in the present 

 case made up in sea water. 



The corpuscles were first removed by means of a hand cen- 

 trifuge; after that they were washed once more with about 

 one c.c. of seawater. When sodium carbonate was added in 

 order to produce the blue color, a slight precipitate came down. 

 This precipitate was removed by means of the centrifuge, before 

 the colometric reading was made. 



In that way the results represented in table 1 1 were obtained 

 in a series of glucose experiments. The quantities injected were 

 75, 150, 350 and 700 mgr., which covers a wide range. On 

 the average — 6 animals were used — a starfish appeared to 

 contain 22 c.c. of perivisceral fluid. On this assumption and 

 given the quantity of liquid in which the sugar had been dis- 



