226 NATURAL SCIENCE. April. 



animals, Dr. Merriam added together the effective temperatures or 

 degrees of normal mean daily heat in excess of the minimum at each 

 station, beginning from the time in spring when the normal mean 

 daily temperature rises above the minimum, and ending at the time 

 in autumn or winter when the normal daily mean falls again to the 

 minimum. By means of such data he plotted out zones on the map 

 bounded by isotherms, and found that they corresponded in a " most 

 gratifying manner to the northern boundaries of the several life- 

 zones." " While the available data are not so numerous as might be 

 desired," he says, " the stations in many instances being too far 

 apart, still enough are at hand to justify the belief that animals and 

 plants an restricted in northward distribution by the total quantity of heat 

 during the season of growth and reproduction.' n Dr. Merriam's paper 

 is illustrated by maps, and is well worthy of attention from all 

 biologists. 



Mr. Scott Elliot's African Journey. 

 A special interest attached to the Linnean Society's meeting on 

 the evening of March 7 in the presence of Mr. G. F. Scott Elliot, 

 who had returned only the day before from a two years' journey of 

 exploration in tropical Africa. Mr. Elliot has suffered severely from 

 fever during the last five months of his trip, but the voyage home 

 seemed to have restored him, as he appeared in excellent health. 

 From the few words in which the traveller described his journey and 

 some of its most striking impressions, it is evident that the work of 

 the past two years will yield valuable results, not only to science, but 

 also in the way of opening up the country to civilisation and commerce. 

 The route followed was from the east coast at Mombasa to Uganda 

 and the Nyanza, whence, owing to political disturbances, a much 

 desired trip to Mt. Elgon proved impracticable. Turning south, Mr. 

 Elliot followed the Kagera river some distance up from the lake, 

 and found it to be navigable. On Mt. Ruwenzori four months were 

 spent in exploration and collecting. The working-out of the collec- 

 tions promises much information, not only on the flora and fauna 

 of the mountain in particular, but on African problems of geographical 

 distribution in general. Only one specimen was before the Society, 

 a new giant Lobelia rivalling those already known from Kenya, 

 Kilima-njaro, and the Cameroons. Leaving Ruwenzori last August, 

 Mr. Elliot made his way southwards, after a perilous journey, to the 

 head of Lake Tanganyika, down this lake, and then down Lake 

 Nyasa to Blantyre. A trip to Mt. Milanji was rendered futile by a 

 serious attack of fever, which suggested to the explorer a speedy 

 return to England, via Chinde and Zanzibar. 



West Indian Liverworts and African Plants. 

 The recent publications of the Linnean Society contain contri- 

 butions of some importance in the field of Systematic Botany. 



