738 CALIFORNIA ACADEMY OF SCIENCES. 



Mazatlan, from there to San Bias, thence to the City of 

 Tepic, inland. After a month or more exploration in this 

 vicinity, the members of the expedition returned via Ma- 

 zatlan, Guaymas, etc., to San Francisco in December. 



This, however, was not the first expedition of its kind, 

 the Academy having previously sent out five different ex- 

 peditions, the writer being a member of two of them, hav- 

 ing thus had occasion to visit the Cape Region of Baja 

 California for scientific purposes three times. 



The expeditions have received many and constant 

 courtesies from the Pacific Coast Steamship Company 

 and its agents in Mexican ports, and also from the oflicers 

 of their steamers, particularly from Captain John von 

 Helms and Purser W. A. Childs. 



TEMPERATURE AND CLIMATE. 



As might be expected from a small peninsula situated 

 just within the boundaries of the tropics and surrounded 

 by water, the temperature is a moderate one. All along 

 the low lands up to 800 feet or thereabouts, we meet at 

 no time of the year with frosts. In the San Jose Valley 

 the frost free belt extends as far north as La Palma, but 

 as the valley steadily but slowly rises towards the upper 

 end, we find that at Caduano and Miraflores during the 

 cold winter months, January and February, light frosts 

 may now and then occur. In the vicinity of these places, 

 situated about 1000 feet above the ocean, frosts have been 

 known to kill back the native vegetation, especially the yel- 

 low flowering shrubs known as " palo de arco " ( Tecoma 

 stans). But from San Jose to La Palma no such frosts have 

 ever been noticed. All along the coast, however, on one 

 side to Todos Santos, on the other to La Paz, frosts at any 

 time are unheard of. Similarly, as we ascend in the 

 mountains, light frosts may be expected. Both at El 

 Taste and at Sierra Laguna ice is frequently formed 



