i8 95 . NOTES AND COMMENTS. 297 



over the body, doing no damage save to the nerve-centre controlling, 

 say, the mechanism of respiration. 



In some cases the toxins have been prepared from cultures of the 

 microbe on gelatine or agar-agar, and these toxins, carefully separated 

 from the parent-bacteria, cause the dangerous symptoms of the 

 disease, when they are introduced directly into the blood. 



The anti-toxins are more difficult to understand. It seems that, 

 as the toxins are discharged into the blood, the blood "makes an 

 effort" to neutralise them by producing a counteracting proteid 

 substance. In some animals it appears as if the anti-toxin for a 

 particular toxin was present naturally, and such animals would 

 naturally be immune to the ravages of the microbe in question. But in 

 all animals, if the toxin be supplied slowly, there is an effort made to 

 manufacture the counteracting agent. The secret of anti-toxin treat- 

 ment is to select an animal constitutionally able to manufacture the 

 anti-toxin of any particular toxin ; to stimulate the production by 

 gradually increasing doses of the toxin, and then when the blood is 

 filled by the anti-toxin to remove and isolate the latter. When the 

 anti-toxin, so prepared, is injected into the blood of a patient suffering 

 from the disease, it neutralises the toxins in process of being dis- 

 charged ; and when the most dangerous symptoms have been 

 mitigated, no doubt the tissues are enabled to manufacture the 

 necessary further supply of anti-toxin themselves. 



Such is the general theory of toxins and anti-toxins ; in each 

 particular case there is still needed experience and experiment. 



The Sexual Organs of Ferns. 



Mr. D. H. Campbell communicates to the Botanical Gazette (of 

 February) a note on the origin of the sexual organs in Ferns. A study 

 of the development of Marattia led the author to conclude that this 

 genus and its nearest allies had arisen from forms resembling 

 Anthoceros, a somewhat peculiar genus of Liverwort. The sexual 

 organs in Anthoceros differ from those generally characteristic of Mosses 

 and Liverworts, in that they are buried in the tissue of the plant-body 

 and are not protruded and borne on stalks. The female organ, in 

 particular, is of more simple structure, recalling that of Marattia, and, 

 to a less extent, of the more typical ferns. The author is convinced 

 that, in tracing the pedigree of the Fern group as a whole, we must 

 work back through forms like Marattia to a moss-ancestor resembling 

 Anthoceros. 



Botanical Education in America. 



In the same number, the editor strikes a note of warning a propos 



of methods of botanical instruction prevalent in American colleges, 



not, he says, those " in which botany receives but little attention," 



but " those in which there is an attempt to develop it in a full and 



