ir> EXPERIMENT STATION KECORD. 



that till' availal)l(> tfini>fratun' at Toulon on tlio ^lediterraiu'aii is about 4600° C. us 

 (•oniparfd to 2750° for t lie vicinity <if Paris. The most striking difference between 

 the 2 re^iions is the oirurreiice of (lellnite wet and (h-y seasons in the ^h^diterninean. 



The plants exi)eriniented upon were trees and shrubs, mostly beeehes, mull)erries, 

 loeusts, linden, ash, lilae, and euonymus. In <jceneral the trunks and spring' wood 

 were best develoi)eil in the .Mediterranean region. The vascular system was larger 

 and more abundant in the spring growth in the same species of jjlant cultivated in 

 the Mediterranean than at Fontainebleau. The i)arenchyma was more lignified at 

 Toulon and this lignifieation was affected mostly during the period of drought. The 

 leaves of the arborescent species were thicker at Toulon than at Fontainebleau, the 

 palisade parenchyma in some cases being 2 or 3 times as thick as in the more 

 northern-grown plants. 



Among the other adaptations whicli were attributed to the climatic conditions 

 were those in leaves to reduce transjjiration during periods of drouglit. This was 

 affected most in the plants grown near the 3Iediterranean. While the stomata were 

 very mnnerous they were often completely closed and <lepressed in the surfai'e of 

 the leaf. Annual species of plants whose stems died down during a period of 

 drought did not show any of these modifications whii-h are described for the 

 perennial species. 



The upper temperature limits of life, W. A. Setchell [Science, n. ser., 17 {1903), 

 No. 441, jiji. OJ4-9o7). — An account is given of investigations of the organisms inhabit- 

 ing hot springs, in which an attempt was made to ascertain the upper temperature 

 limits of plant life. In the aut!ior''s investigations it was found that unless consider- 

 able care was exercised the accurate temperature of the thermal springs woulil not 

 be correctly ascertained. Special precautions were taken to determine accurately 

 the temperature of the waters, and the results of the observations are given at con- 

 siderable length. For the strictly thermal waters, that is, those having temperatures 

 of 48 to 45° C. or above, no animals were found, although careful search was made 

 for them, nor were any living diatoms discovered under such conditions. The only 

 organisms found were groups of plants belonging either to the Schizophyceaj or 

 Schizomycetes. The chloropliyll-bearing members of these groups continued com- 

 mon in temjieratures up to 65 or 68° C, and in some cases, although not so abundant, 

 at 75 to 77°. The chlorophylless Schizomycetes are apparently able to endure the 

 highest temperatures of living organisms, as they were found abundant at 70 to 71° 0. 

 and remained in considerable quantity at 82 and 8!)°. The temperature of 80° C. 

 was the highest at which the author was able to find any living organisms. 



Living organisms were found at higher temperatures in siliceous waters than in 

 calcareous waters. The limits of life in the siliceous waters were determined l>y the 

 author's observations to be between 75 and 77° for the c^hlorophyll-bearing and 89° 

 for the chlorophylless i)lants. In the calcareous waters the limits of endurance were 

 between 00 and (V.]° for the chlorophyll-bearing Schizophyta and 70 and 71° for the 

 chlorophylless species. No organisms were fountl in springs which had a decided 

 acid reaction. A careful study of the species of thermal Schizophyta showed that 

 they were either fdamentous or unicellular, but in each case the filaments or (>ells 

 were inchwed within an abundant mass of jelly. 



Chemical stimulation and the evolution of curbon dioxid, 1\. B. Copeland 

 {Bol. (luz., 35 {1903), A'o.s'. 2, pp. 81-9S; 3, jip. 100-183, Jigsi. «').— While engaged in a 

 study of the poisonous properties of certain chemicals, the autlior noted the accelera- 

 tion of growth in many of thecultures, which led to a. series of studies in water cultures 

 to detennine the cause of this variation. In considering the growth of the plants the 

 increased res])iration ^\as taken as the factor to be considered, and the effect of 

 various substances on the liberation of carbon dioxid was examined. The methods 

 are descrilied in detail. As subjects of the experiments the author used various 

 aquatic plants, such as Cardamine, Callitriche, Ceratophyllum, Potamogeton, Elodea, 



