80 CARNEGIE INSTITUTION OF WASHINGTON. 



Ten rain gages set out in 1919 were visited and all found intact. 

 Data were also obtained from two lighthouses, Point Pinos and Point 

 Sur. These 12 stations may be classified as follows: 



Stations 1 to 3 represent the low sand-dune country east and north- 

 east of Monterey; 4 to 7 the Monterey pine forest of the Monterey 

 Peninsula and its immediate surroundings; 8 is on the summit of a 

 mountain ridge (altitude 330 meters) between the sand-dune country 

 of Monterey Bay and the Carmel River; 9 is in the narrow Carmel 

 Valley between the ridge of station 8 and the Santa Lucia Mountains; 

 10 to 12 (north to south) are on the mountainous coast (Santa Lucia 

 Mountains) south of the Carmel River. 



Two generalizations may be made: (1) The mountains are the evi- 

 dent cause of the striking differences in precipitation in this limited 

 extent of country; (2) precipitation is not a factor in the explanation 

 of the presence of luxuriant pine forest on the Monterey Peninsula. The 

 precipitation studies will be continued through the coming rainy season. 



Atmometer studies carried on during the summer of 1919, now tabu- 

 lated, show that the evaporation rate in a variety of situations on the 

 Monterey Peninsula is decidedly less than in the oak and chaparral 

 country east of Monterey. This factor may therefore be a partial ex- 

 planation of the persistence of the pine forest on the peninsula. 



In the sand-dune succession as studied in the region east and north- 

 east of Monterey, the evaporation-rate decreases and the soil moisture 

 increases as the succession advances toward the climax. 



The quadrat studies have not yet advanced far enough to yield 

 results of importance. Facts of interest observed after the passing 

 of one year are the destruction of luxuriant mats of Franseria by sand 

 from an active blowout; the very perceptible increase in the vegetation 

 cover on the lee slope of a sand trail where the sand movement has 

 practically spent itself ; the increase in average radius, during the last 

 growing season, of 1 decimeter in a plant of Arctostaplujlos pumila 

 5 meters in diameter ; and the absence of perceptible increase in a simi- 

 lar but much older plant 10 meters in diameter. 



Some Structural Features of the Chlorophyll-bearing Organs of Perennials of 

 South Australia, by W. A. Cannon. 



The structure of the organs of whatever morphological nature which 

 carry on the photosynthetic processes in perennials of the more arid 

 portions of South Australia show striking adjustments to water and 

 light and are of especial interest.^ The organs which contain chloro- 

 phyll are leaves, leaf stalks (phyllodia), or stems, and notwithstanding 

 the diverse morphological origin and relations a marked parallehsm 

 in the direction of the development of their tissues may be found. Thus 

 the striation of the exceedingly long leaves of Hakea muUilineata, that 



^ Compare Carnegie Inst. Wash. Year Book for 1919, pp. 90-92. 



