258 



SCIENCE. 



[N. S. Vol. XI. No. 268. 



usually rapid, the chlorophyll bearing 

 organisms, especially the green flagellates 

 appearing first, followed in turn by the 

 animal plankton, Protozoa, Rotifera and 

 Entomostraca. The resubmergence of the 

 bottom lands doubtless starts anew encysted 

 forms left by receding waters. In general 

 the recovery from the flood culminates in 

 a plankton maximum of greater or less im- 

 portance, depending upon the season of the 

 year and the exteut of the flood. 



9. Species present in great numbers are 

 often extremely variable, as for example, 

 Braehionus bakeri. The varieties are often 

 local, or seasonal, but may also be coex- 

 istent. Variation is often very great in the 

 case of species reproducing parthenogenetic- 

 ally as the rotifer just mentioned, in other 

 rotifers, in Daphnia and in Bosmina. 



C. A. KOFOID. 



MALARIA AND TUBERCULOSIS* 

 The visit of certain English physicians 

 to Italy during the Christmas vacation, 

 was in some respects so remarkable as to 

 make a full description of it of general in- 

 terest. Commendatore Florio, a wealthy 

 and beneficent citizen of Palermo, invited 

 certain English physicians first to Rome, 

 in order to see the work done by their Ro- 

 man brethren in the investigation of ma- 

 laria ; and, secondly, to Palermo, to inspect 

 a sanatorium for the cure of consumption 

 which Commendatore Florio has erected 

 under the advice of Professor Cervello, of 

 the University of Palermo. The party of 

 English physicians with their friends was 

 about twenty in number, among them being 

 Sir T. Lauder Brunton, Sir Walter Foster, 

 M.P., Professor Clifford Allbutfe, of Cam- 

 bridge,Dr. Manson,C.M.G.,and Dr.Cantlie, 

 of the London Tropical School. Dr. Mal- 

 colm Morris and Dr. St. Clair Thompson 

 represented the National Association for 

 * From the London Times. 



the Prevention of Tuberculosis, and Dr. 

 Gibson represented Edinburgh. They were 

 received at Charing-cross Station by Com- 

 mendatore Florio's representative and 

 travelled with him to Rome, where they 

 remained for some days in conference with 

 Professors Grassi, Bignami, Celli, and Bas- 

 tianelli. Signor Grassi, now Professor of 

 Zoology in the University of Rome, is a 

 Sicilian, and while a professor at Catania 

 carried out the remarkable researches on 

 the propagation of the eel which secured 

 for him the Darwin Medal of the Royal 

 Societ3\ 



Professor Grassi, since his removal to 

 Rome, has performed work perhaps no less 

 remarkable in demonstrating the propaga- 

 tion of malaria. This story is not onlj^ so 

 interesting in itself, but of such vital im- 

 portance to our own colonies, some of 

 which are desolated by malaria, that I will 

 try to sketch briefly what will be told in 

 full by Professor Grassi in an illustrated 

 volume to appear very soon both in Italian 

 and English. A few years ago M. Laveran 

 won a place for himself on the distinguished 

 roll of Frenchmen of science by discovering 

 in the blood of malarious patients a minute 

 parasite, a form belonging to the humblest 

 order of animal life. Three difierent but 

 closely allied species of parasite are severally 

 concerned in the causation of the three 

 kinds of malarial fever. M. Laveran's re- 

 searches were fully verified by observations 

 both in Europe and in America, and further 

 observations made of their behavior in man. 

 Certain suggestive facts led Dr. Manson to 

 suspect that a gnat or gnats were the means 

 of propagating the parasite, and, having 

 himself returned from the tropics, he pressed 

 Major Ross, then of the Indian Medical 

 Service, to follow up this clue in India. 

 Himself an ardent engineer and now chief 

 of the Liverpool Tropical School, Major 

 Ross set to work with some success, but 

 unfortunately his efifbrts were impeded by 



