ECOLOGY. 321 



the Garden of the Gods in the Petran chaparral, one containing sod from 

 the upper edge of the montane forest, the other a sod from the alpine meadow. 

 At the Alpine Laboratory are two corresponding quadrats with sods from the 

 chaparral, the alpine meadow formation, and reciprocal ones are located in 

 the alpine meadow. 



A number of lichen and moss quadrats have been established for the purpose 

 of measuring quantitatively the rate of change and the composition of the 

 earlier stages of the xerosere. These are not charted in the ordinary manner 

 but arc photographed. Two sizes are used, one a decimeter square, which is 

 photographed natural size, and more commonly one 2 dm. square, which is 

 reduced to one-half in the photograph. The latter are mostly paired and one 

 quadrat in each pair has a square 8 cm. in size chiseled out of the exact center. 

 The rock in most cases has been bared to sufficient depth to expose a prac- 

 tically unweathered surface. In certain of them, lichens or mosses have 

 been transplanted by attaching them to the rock in various ways. 



Grazing Research, by F. E. Clements, J. V. G. Loftfield, and H. M. Hall. 



The regular field work on the relation of vaiying rainfall to the composition 

 and carrying capacity of the range, on the indicators of optimum grazing and 

 overgrazing, and the effects of the latter has been carried on in the various 

 climaxes throughout the year. Several new exclosures have been installed, 

 and a large number of additional quadrats, transects, and tristats estabhshed, 

 especially on the Santa Rita Range Reserve, in northern Arizona, and at the 

 Sonora Substation in western Texas. 



In the Sierra Nevada several small exclosures have been fenced on the 

 westerly slope at 4,500-feet altitude, and two in the sagebrush association 

 at a similar altitude on the east side of the range, while extensive protected 

 areas at Tuolumne Meadows in the Yosemite National Park will serve a 

 similar purpose for species adapted to high altitudes. These ^reas, all of 

 which have been previously overgrazed, are intended to serve as stations for the 

 study of succession and of ecology of forage plants of this particular region. 



Research in Hay-Fever. 

 Pacific Coast and Great Basin, by H. M. Hall. 



Cooperative studies with clinicians and practicing specialists on the Pacific 

 Coast have been intensified during the year. In addition to the more ele- 

 mentaiy work, such as the preparation of pollen surveys and the investiga- 

 tion of hay-fever pollens, a beginning has been made in the fundamental 

 principles of group reactions. It now seems probable that a correct botanical 

 classification, when once worked out, will indicate the limits to which the prac- 

 titioner can go in assembling the species of pollen plants into groups, any mem- 

 ber of which ma}^ be used interchangeably with any other of the same group. 

 The principle underlying this method is that both the botanical and the 

 clinical groupings are at base chemical in nature. 



In order to test the parallelism between the botanical arrangement and the 

 pollen reactions, there have been prepared lists and charts showing the 

 different degrees of relationship between species of several of the more im- 

 portant genera and families. These are now used as a basis for experiments 

 as suitable subjects become available in the clinics. Prehminary experiments 

 seem to indicate that in certain plant famihes the proteids are closely similar 

 even in different genera, whereas in other families there is a sharp distinction 

 between the reactions obtained even from species of close relationship. 



