BOTANICAL RESEARCH — MACDOUGAE. I27 



to the Everglades, the results of which have appeared in print; the inves- 

 tigation was taken up anew October i, and it is not possible to present the 

 advanced results obtained at this time. 



Morphology and Physiology of Storage Organs, by Dr. D. T. Mac- 

 Dougal. — A comprehensive examination of the water-storing functions in 

 plants of arid regions has been begun in which the physiological as well as 

 the morphological aspect of the subject is taken into consideration. The 

 adaptations for accumulating and holding a reserve suppl}' of water occur in 

 all parts of the root and shoot of various species of seed-plants, and the 

 development of tissues for this function shows some important morphological 

 features. So far as a general survey of American deserts has been made it 

 seems justifiable to conclude that storage organs and storage plants are most 

 abundant in regions in which the scant rainfall comes within a limited period 

 in the year, while the remainder of the year is lacking in sensible precipitation. 

 In regions such as those on the lee side of the main range of the peninsula 

 of Baja California, in which the precipitation is very slight, at any time, 

 and in which the total is small, very few plants are found with well-developed 

 storage organs. 



Ihervillea sonorce ("guarequi''), one of the cucurbits, develops a storage 

 organ at the base of the stem, the size of squash, which is furnished with a 

 heavy outer covering highly resistant to evaporation. During the dry season 

 these structures lie on the surface of the hot sands unaffected. With the 

 beginning of the rainy season roots are quickly formed, shoots are sent up, 

 and fruit and seed quickly matured, when the thin stems die away and the 

 guarequi goes into a resting condition for another year. Some of these 

 plants were collected and placed on a dry shelf in a museum case in February, 

 1902, where they have since remained. Every year since, at a time cor- 

 responding to the rainy season in the native habitat, thin stems have been 

 sent up, which after a time die back after having developed leaves. Five 

 years' growth has thus been made at the expense of water stored up in 

 October, 1901, and the great storage organs are still sound and give evidence 

 that they may furnish supplies for the annual formation of stems and leaves 

 for a decade. A large number of species from the desert show similar 

 adaptations. 



Bxplorations and Field Work, by Dr. D. T. MacDougal. — The original 

 sketch of some of the better known deserts of North America made by Dr. 

 MacDougal and Mr. Coville has proved so useful in the organization of 

 researches and has afforded so much information that it has been deemed 

 advisable to extend the work to include areas not previously examined. In 

 accordance with this plan a visit was made to the sage-brush deserts of 

 northern Nevada, to the arid and saline areas contiguous to Great Salt Lake 

 in Utah, and to the great bolson of Las Vegas, in southern Nevada, all of 



