I02 CARNEGIE INSTITUTION OP WASHINGTON. 



The subjects include : (i) The cytology and development of Diplo- 

 phrys. (2) The morphology and development of Ceratiomyxa. 

 (3) On the cell organization of the larger bacteria. (4) On the 

 cytology of various blue-green algae. (5) On the cytology and 

 general morphology of various species of the Kntomophthorese. 

 (6) The morphology of Monasais purpure2is. 



One paper on the blue-green algae is in press, another on Monascus 

 is almost ready for the publishers, while considerable progress has 

 been made, particularly on problems 2 and 5. Of special interest is 

 the discovery that the nuclei of the blue-green algae are, under 

 ordinary conditions, in a state of continuous mitotic activity, the 

 division occurring with more or less rhythmic regularity. Further, 

 the large nuclei of Empusa appear to present a somewhat new type 

 of karyokinetic division. They possess intranuclear division centers 

 and their minute chromatin granules do not become aggregated into 

 definite chromosomes. 



V. M. Spalding, Tucson, Arizona, Grant No. 189. For investigation 

 of absorption a^id transpiration of zvater by desert shrubs. $600. 

 Abstract of Report. — (i) The creosote bush maintains life for 

 long periods in a soil which gives up on drying no more than 3 per 

 cent of water ; it also grows in completely saturated soil. Plants 

 grown in pots three months, which were supplied with 53 ounces 

 of water during that period, made a scarcely less vigorous growth 

 than one which received no ounces in the same time. An accu- 

 mulation of similar facts will make it possible to give quantitative 

 expression to the power of adaptation of this species to extreme 

 conditions of water supply. 



(2) The creosote bush maintains regular transpiration after long 

 periods of excessive drought. Experiments during the present year 

 have shown that the rate of transpiration is determined primarily 

 by the amount of water available in the soil. The action of other 

 factors is conditioned upon this. Thus direct sunlight accelerates 

 the rate of transpiration if the plant has a full supply of water, but 

 not otherwise. 



(3) As indicated by plasmolysis, the actively absorbing cells of 

 the roots are capable of taking up water with a force equivalent to 

 upward of ten atmospheres. 



(4) The production of root-hairs is increased within certain limits 

 by lessening the water supply. Regeneration of root-hairs takes 

 place when water is abundantly supplied to a plant that has been 

 living in dry soil. 



