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SCIENCE. 



[N. S. Vol. XIX. No. 493. 



increasing the osmotic pressure. Bernard 

 has also shown that beyond an early stage 

 the germination of seeds of the orchids 

 Cattleya and Lcelia is quite dependent upon 

 the penetration of an endophytic fungus 

 into the minute embryo. Aseptic cultures 

 into which the fungus is introduced at once 

 show vigorous growth. Thus, as Bernard 

 states, the orchid seedling is dependent 

 upon a fungus for its development, much as 

 an egg is dependent upon fertilization. In 

 this connection it may be noted that Pinoy 

 succeeds in getting Myxomycete cultures 

 only in the presence of bacteria, while Mol- 

 liard finds that the development of peri- 

 thecia in Ascobolus is highly favored by 

 the presence of other fungi in the culture. 

 The mycorhiza literature has received sev- 

 eral additions during the year, but no 

 marked advance has been made in our 

 knowledge. Moller thinks that root fungi 

 have little or no significance in the nutri- 

 tion of green plants. Tubeuf , on the other 

 hand, holds to the common view. Neger 

 shows that the reason why autotrophic 

 plants flourish better in sterilized soils is 

 because of a change in the soil rather than 

 in the absence of fungi, as Stahl supposed. 

 Among the important papers of the year 

 we must, of course, include MacDougal's 

 study of the influence of light upon the 

 life of plants; his general conclusion that 

 light does not directly influence growth is 

 of great import in ecology, as is the view 

 that light favors the differentiation of tis- 

 sues. Eberhardt has now given us a de- 

 tailed account of his studies concerning the 

 influence of dry and moist air upon plant 

 tissues, but thei'.e are few general results 

 which he failed to outline in his prelim- 

 inary notice. We may note Winkler's 

 study of the causes of leaf position, in 

 which Schwendener 's pressure theory is 

 opposed, though most of Winkler's papers, 

 as well as the polemics which they occa- 

 sioned, antedate the year now closing. The 



regeneration studies of Winkler, Goebel 

 and several others have an ecological bear- 

 ing but time will not permit their consid- 

 eration. Bonnier has made some interest- 

 ing morphological experiments on orchid 

 roots, as has Benecke on the thalli and 

 rhizoids of liverworts. Benecke finds that 

 impurities in the glassware commonly em- 

 ployed in laboratories are responsible for 

 some results, and in this connection we 

 should note the work of Singer and Richter 

 upon the influence of laboratory air in ex- 

 perimental cultures. These and other con- 

 siderations demand that as much work as 

 possible should be done out of doors, or at 

 least in well-controlled greenhouses. From 

 an ecological point of view much experi- 

 mental work that is done in the laboratory 

 or even in the greenhouse is of no direct 

 value. Ganong, in his marsh paper, makes 

 an appeal for field laboratories in connec- 

 tion with fiiture ecological work, and it 

 must be admitted that his argument is 

 sound. The tropical laboratories and the 

 recently installed desert laboratory are 

 steps in the right direction, but even in 

 these cases the experimental work which is 

 to be of the greatest ecological value, must 

 be performed not in the laboratories, but 

 out of doors. In this, which the speaker 

 believes to be the most promising line of 

 ecological research, Bonnier has led the 

 way in his magnificent experiments upon 

 alpine plants. During the past year he 

 has reported tipon his parallel cultures at 

 Paris and Toulon, in which portions of the 

 same individual plant and identical soils 

 are employed. He finds that his Toxilon 

 eidtures from Paris plants are showing 

 characters which the same species show in 

 nature about Toulon, a result in harmony 

 with his earlier alpine studies. 



Among contributions based more on ob- 

 servation than experiment are: Paul on 

 the biology of moss rhizoids, in which he 

 maintains that they are primarily of valiie 



