and Laboratory Methods. l"ll 



plete individual. Double footed hydras can be produced by longitudinal split- 

 ting of the aboral end of the normal individual. If two individuals are grafted 

 together with either the oral or the aboral surfaces together and then each com- 

 ponent is cut off close to the line of junction, a head will form on one cut surface 

 and a foot on the other, the polarity thus being reversed in one component. 

 When pieces from five hydras are grafted together a single individual is not 

 formed, nor can each component of such a graft maintain its individuality and 

 form a complete polyp. Instead, as many individuals are formed from such a 

 graft as there are heads produced. If the component parts of a graft are of 

 nearly the same size, each part tends to maintain its individuality and produce 

 tissue like itself, while if one component is markedly smaller than the other the 

 smaller part is usually resorbed. R. p. 



Rothberger, J. C. Ueber die gegenseitigen Be- The author finds as a result of an ex- 

 ziehungen zmschen Curare und Physostig- tended series of experiments on frogs, 

 min. Arch. f. d. ges. Physiol. 87: 117-169, ^ 11 -^ j j ^\. ^ ..u • 



Taf. Ill and IV, 1901. cats, rabbits and dogs that there is 



a complete and mutual antagonism 

 between the drugs curare and physostigmin in respect to their physiological 

 action. A muscle which has been paralyzed through the action of curare can 

 again be set into activity within a few seconds after an injection of physostigmin 

 into the circulation. In case of an isolated muscle preparation the physostigmin 

 may be introduced through the artery supplying the muscle itself, with the same 

 result. An animal completely paralyzed with curare regains entire power of 

 movement after injection of physostigmin. The muscles which are the last to 

 become paralyzed by curare, e. g., the diaphragm! are those which first regain 

 irritability as a result of the action of the physostigmin. The effectiveness of 

 the physostigmin is independent of the duration of the curare paralysis. A very 

 curious result is observed if a mixture of the two drugs is injected into the cir- 

 culation. They do not neutralize each other, but instead complete curare paraly- 

 sis occurs, and in about a half hour spontaneously disappears, the animal re- 

 gaining its normal activity. Both drugs act on the endings of the motor nerves 

 in the striated muscles. 



The author points out a practical application of these interesting results 

 which is likely to prove of technical value. This is the use of curare in place of 

 an anaesthetic in difficult operations in ph3-siological experiments. Immobilisa- 

 tion can be made very complete and the animal subsequently revived by the 

 injection of physostigmin. The procedure recommended is as follows : the ani- 

 mal is quieted by injection of about half the amount of curare necessary to pro- 

 duce complete paralysis, and an artificial respiration apparatus is inserted through 

 the larynx into the trachea, and the operation is begun. When the operation is 

 practically completed 2 to 3 mg. of physostigmin and at the same time 

 2 mg. of atropin are injected. . In about ten minutes the respiration apparatus 

 may be removed, the wound in the meantime having been closed with stitches. 

 This method has been found to give excellent results in practice. R. p. 



Hedin, S. Q., und Rowland, S. Ueber ein pro- Enzymes which dissolve albumens have 



teolytisches Enzym in der Milz. Zeitschr. f. , ■' ^ ^ •> r ^i/a-ju^-j 



Physiol. Chem. 32: 341-34Q, 1901. ^een extracted from the fluid obtained 



Untersuchungen iiber das Vorkommen von by crushing and pressing finely divided 



proteolytischen Enzymen im Thierkorper. portions of various organs and tissues 



Ibid. 32: 531-540, 1901. of the animal body. Such proteolytic 



enzymes have thus far been obtained from the spleen, lymph glands, the kidney, 



the liver, skeletal muscle, heart muscle, and blood corpuscles. The enzymes 



from the spleen, lymph glands, kidney, and liver are most active in acid solution, 



while that obtained from skeletal muscle tissue is relatively weaker and shows 



no marked difference in its activity when in acid, neutral, or alkaline solution. 



R. p. 



