ALG.'E. 167 



pains in the back and limbs. These symptoms were 

 soon followed by a well-marked paroxysm of ague. 

 As soon as this occurred the pan of plants came to 

 my mind, and was removed." 



We may pass on to the more precise details which 

 are given of these ague-plants, and it seems to be 

 rather singular that, instead of being referred to well- 

 known genera or species, they should all be placed in 

 three new genera, constructed specially to receive 

 them. It may be added that, during a quarter of a 

 century, these three new genera have failed to secure 

 for themselves a place in systematic algology. One 

 of these genera which includes half a dozen species, 

 which are characterized chiefly by colour, is termed 

 Geniiasma, including " plants having the appearance 

 of cells, each consisting of a thin outside wall, enclosing 

 an inside cell filled with minute spores, either single 

 or aggregated, multiplying by duplicative segmenta- 

 tion within a parent membrane, and also developed 

 from spores." All these genera, it is stated, have 

 spores of a similar structure : the spores are mostly 

 oval, or more or less oblong, and have double walls. 



" The species are many, all of which have hereto- 

 fore been regarded as innocuous. There is strong 

 evidence for believing, however, that the minute 

 species that are developed in such abundance in the 

 above-mentioned localities, and the spores of which 

 become elevated and suspended in such multitudes 

 in the heavy humid night exhalations of ague districts, 

 are decidedly poisonous to the epithelial surfaces with 

 which they come in contact, and are the true source of 

 intermittent and remittent fevers." 



