§ 1] MODIFICATION OF VITAL ACTIONS 25 



Morphin acts less violently upon the nervous tissue of Ver- 

 tebrates. It has a very weak action upon Protista. 



Strychnin, chemically considered, is an alkaloid with the 

 formula: C2iH22^202 5 specific gravity, 1.359 at 18°; soluble 

 to about 0.025% in water at 14.6°; has a very bitter taste. 

 The nitrate is generally employed. The action of strychnin 

 upon Protista is known through the studies of Max Schultze 

 ('63, p. 32), BiNZ ('67, pp. 384-389), Rossbach ('72, pp. 

 52-54), and Schuemayer ('90, pp. 423-433). Keukenbeeg 

 ('80) has studied its effects upon higher Invertebrates. Its 

 action upon sexual cells has been studied by the brothers 

 Hertwig ('87, pp. 153-156, 164). 



Although not fatal to bacteria and only in strong solutions 

 fatal to the large fungi, strychnin is a nearly universal proto- 

 plasmic poison. It kills the protoplasm of the Drosera ten- 

 tacles and hinders the development of peas, corn, and lupines. 

 The amount of strychnin that Protozoa can withstand has been 

 variously stated, while all authors admit considerable individ- 

 ual variation in this respect. Probably Protozoa cannot ordi- 

 narily resist a saturated solution for one minute. Rossbach 

 ('72, p. 52) found that no infusorian of his cultures survived 

 a "0.1 9^ solution" long enough to be placed under the mi- 

 croscope. A 0.02% or 0.01% solution can be withstood for 

 a few minutes (0.01% solution was withstood for 5 minutes, 

 ScHtJEMAYEE). As for the weakest solution that will kill, 

 ScHtJEMAYEE found that a Paramecium resisted for only 15 

 to 20 minutes so weak a solution as 0.0005%, while Rossbach 

 found Stylonychia little affected by a 0.0055% solution. The 

 spermatozoa of Echinoids, according to the Heetwigs ('87, 

 p. 164), so resist a 0.01% solution that after 180 minutes the 

 movement is only somewhat retarded. Echinoid eggs are in- 

 jured in a few minutes by 0.005%. 



The injurious action of strychnin on Protozoa varies in the 

 different groups, the resistance capacity increasing, in general, 

 with the height of systematic position of the group. The 

 first effect in Ciliata is an increased activity of the cilia; if 

 cirri are present, these strike more powerfxilly; locomotion is 

 abnormally rapid ; but the movements lack coordination, and 

 a rotation takes place about the axis of progression. Next, 



