662 UROMYCES ALOES COOKE. 



Plate 23 a-b. — Photo of leaves of Aloe sp. attacked bv Uromyces Aloes. 



Photo by Dr. I. B. Pole Evans. 

 Fig. I a. — Teleutospore sorus of Uromyces Aloes. X 48. 



b. — Teleutospore sorus of Uromyces from Aloe arborcscens just 

 forming,, showing layer of large empty cells above. X I35. 

 c. — Portion of {b) showing binucleate condition of some of the 

 cells. X 590. 

 Fig. 2 a. — Haustorium in epidermal cell of Aloe Transvaal ensis. X 1000. 

 b. — Haustoria showiJiy their intimate relation with host cell 

 nucleus. X 1000. 

 Fig. 3. — Portion of sorus of Uromyces Aloes from Aloe Traiisvaalensis, 

 showing origin of the teleutospore and stalk cell (s). 

 X 1000. 

 Fig. 4. — Portion of sorus of Uromyces Aloes from Aloe Transvaal ensis. 

 Later stage, showing elongated stalk cells and thickening of 

 teleutospore cell walls. 

 Fig. 5 a. — Spermogoniuin of Urom\ces Aloes from Aloe arborcscens. 



X 135- 



b. — Spermogonium from Aloe Transvaal ensis. X I35- 



c. — Spermatium from latter. X 590. 

 Fir. 6 a. — Teleutospores of Uromyces .4locs Cooke from Aloe Transiaal- 

 ensis. X 220. a' in air ; a" in water. 



b. — Teleutospores of Uromyces Aloes Cooke from Aloe arbor- 

 cscens. h' in air; b" in water. 



c. — Germinating teleutospore of Uromyces Aloes from Aloe Traiis- 

 vaalensis. X 220. 



d. — Genninating teleutospores from Aloe arborcscens. X 2'20. 



e. — Distal end of basidium of germinated teleutospore from Aloe 

 Transvaalensis, fixed and stained. X 480. 



f. — Distal end of basidium of germinated teleutospore from Aloe 

 Transvaalensis, fixed and stained. X 220. 



g. — g' shows end of basidium 24 hours after germination of teleuto- 

 spore; g^ same after 40 hours. X 220. 



Botanical Laboratories, 



Union Department of Agriculture, 

 Pretoria. 



Scientific Labour Union. — According to the Neiv 



York Gall of May 11, 1919, three hundred and seventeen scientific 

 and technical experts in the employ of the United States Govern- 

 ment at Washington have formed a labour union to protect their 

 personal interests and to promote the cause of science. Dr. 

 Rodney H. True, of the Department of Agriculture, is president 

 of the new union. Its objects are — 



1. To improve conditions and facilities for scientific work 

 in the government. 



2. To present the needs and the results of such work to the 

 public and to legislative and administrative public ofificials. 



3. To secure greater freedom of the members in official and 

 unofficial action. 



4. To secure reasonable and just salaries for services per- 

 formed and in accordance with present economic and social con- 

 ditions. 



5. To secure greater recognition in America of the research 

 advancement performed by the scientists and technical experts 

 as essential elements in our national life. 



