be found : by the nature of the work in a summer laboratory one 

 can scarcely expect to exhaust a subject like the one taken up here. 



I must mention however that the phenomena observed re- 

 semble closely those caused by the 

 toxic action of the ,,poison-glands" of 

 the Cephalopodes. 



R. K r a u s e (Zentralbl. f. Phy- 

 siol. 9. 1895. S. 276), who was the 

 first to study these, observed ,,zuc- 

 kende Bewegungen der Extremitaten" 

 in poisoned animals, followed by a 

 gradual weakening till death. The 

 same initial stimulation is indicated 

 here. 



Lo Bianco (Mitt. Zool. Stat. 

 Neapel. Bd, 1 3. 1 899. S. 530) describes 

 a ,,incertezza della locomozione, sub- 

 entrando poco dopo movimenti con- 

 vulsivi, con un tremito rapidissimo 

 in tutti i piedi toracici," which is 

 also followed by death. 



A. Briot (C. R. Soc. Biol. 1905 

 (T. I), p. 315) also mentions the ,,tre- 

 mulations des membres". 



These few indications will serve 

 to show that there is a certain ana- 

 logy between these poisons, at least 

 as far as their action is concerned. 

 Frogs seem to be sensitive to the 

 cephalopode-poison, according to 

 Krause. Briot however denies this, B a g 1 i o n i 3) solves 

 this controversy by showing that the poison can only act here 

 after 1020 minutes, when true typical attacks of clonic con- 

 tractions occur. In our experiments we also find contractions 

 occurring after a considerable length of time. 



The poison of the cephalopodes, is according to Baglioni, 

 a poison of the C. N. S., which first produces clonic contrac- 

 tions, followed by a ,,Lahmung" of the central functions 

 afterwards. It seems to be of phenolic nature and this is the 

 more probable since crabs are very sensitive to phenoles. 



The analogy between these two poisons has also been seen 

 by Pier on 100), who gives as a possible explanation ,,une 

 egale action chimique provenant de secretions, liees a Tappareil 

 digestif, secretion de I'estomac chez 1* Asterie, secretion de la 

 glande salivaire chez le Poulpe." 



A closer investigation of the relation of this poison and the 

 ,, omnipresent" substance in these animals, which is colored blue 

 by Folin-V/u's uric-acid reagent, seems most promising. 



2 



Fig. 2. 

 Control-muscle. 



