1900] MICROSCOPICAL JOURNAL 340 



parasites had dispppeared. A week later the young man 

 was well again. Another interesting experiment conduct- 

 ed this summer was that of Drs. Sambon and Low, who 

 took a hut with them to the most intensely malarial sec- 

 tion of the Roman Campagna. Here they lived for sev- 

 eral weeks without developing malaria, although new- 

 comers to that region almost invariably became promptly 

 infected. All that they did was to remain in the house 

 between sunset and sunrise, and took unusual precautions 

 to prevent being bitten by mosquitos at any time while 

 there. The connecting link between these two most im- 

 portant experiments was to be found in the discovery 

 within the bodies of these mosquitos, known to transmit 

 malaria, thefiagella, thus demonstrating beyond all doubt 

 that the mosquito is the intermediary host of the malarial 

 parasite. It should be noted that this statement applied 

 only to certain species of mosquitos, and this explained the 

 fact that malaria was unknown in many places where or- 

 dinary mosquitos were abundant. 



BIOLOGICAL NOTES. 



L. H. PAMMEL. 



Pollen in Maize. — In a recent bulletin of the Division 

 of Vegetable Physiology and Pathology, Dr. Herbert J. 

 Webber discusses the interesting subject of Xenia or the 

 Immediate Effect of Pollen, in Maize. A great deal of 

 work has been done on the immediate effect of pollen in 

 maize, but the experiments given by Devries and Correns 

 in which attention is called to the fact that double fecun- 

 dation probably explains the phenomena of Xenia. And 

 it is interesting to note that in July, 1899, the same ex- 

 planation seemed probable to Webber. And during that 

 summer quite a number of experiments were conducted 

 with a view to obtain evidence on this question. Double 

 fecundation was first observed in Lilium martagon and 



