ECOLOGY. 345 



a reduction of 50 to 70 per cent of the sun efficiency in the case of ecads 

 growing in sliade of 0.04 intensity. As would be expected, there proved 

 to be a wide variation in the amount of photosjTithate made by the spe- 

 cies of the same shade community, some exhibitmg an efficiency 3 to 5 

 times as great as that of others. 



During the present summer attention has been centered upon sun 

 and shade fomis of the same species and upon sun and shade leaves of 

 the same shi-ub or tree. There is some evidence that species which 

 gi'ow normally in the shade have a higher photosynthetic efficiency 

 than the shade ecads of sun species, and this fact has been given especial 

 attention. A large number of samples has been taken on successive 

 days, as well as on the same day to serve as checks. Recording photo- 

 meters have also been used for the first time to determine the com- 

 plete curve of light intensity for the day. 



Experimental Taxonomy, by F. E. Clements and H. M. Hall. 



The total number of transplants now in position is approximately 

 900. About 70 per cent of the transplants made in 1919 are growing in 

 their new en\TLronment and, since 5 plantmgs are usually made of each 

 form, only 8 species have been lost. The somewhat high mortality was 

 due chiefly to the very unfavorable climatic conditions in California, 

 where the highest percentage of deaths occurred. A new garden has 

 been estabhshed at 8,000 feet to accommodate plants brought up from 

 the plains. This comprises 97 beds, about half of which contain species 

 of Pentstemon, brought together for the study of variation and com- 

 petitive pollination. Another garden has been established at 12,000 

 feet and above timber-line, into which have been transplanted 51 species 

 from middle and lower altitudes. An alpine garden has been started 

 at the plains station, with 30 species represented. 



Most of the reciprocals now established have been subjected to the 

 impact of their new environment for only one year, and none of them 

 for more than two years. While it is too early to expect marked re- 

 sults, a change has already taken place in a few instances. These are 

 ecads, the characters of which are easily modified. For example, the 

 sun-form of Smilacina stellata has glaucous leaves which are folded 

 longitudinally and make a sharp angle with the stem. In the shade- 

 form, the leaves are flat and horizontally spreading and not glaucous. 

 These have characters that have been used in taxonomic keys for the 

 separation of supposedly distinct species. After plants of the sun- 

 form have been grown in moist shady places for a single season, the 

 leaves are identical with those of the shade-form. Conversely, when 

 transplants are taken from the shade and placed in open sunny spots, 

 the leaves become glaucous, tend to fold longitudinally, and assume an 

 ascending position. These results have been checked by removing 

 the leafy canopy above plants of the shade-form without disturbing the 



