JuxE 10, 1910] 



SCIENCE 



913 



fungus ■when it first develops on the under 

 side of an orange leaf in larvK of the white- 

 fly, forms a chocolate-brown (Saccardo's color 

 chart, No. 10) stroma, which somewhat re- 

 sembles the citrus red scale, Chrysomphalus 

 aonidum. From the margins of this stroma 

 there extend colorless thick-walled hyphae. 

 This stage of the fungus is sterile, and in this 

 condition it was described by Webber under 

 the name of " Brown fungus." 



In the later development of the fungus 

 (usually in the summer or fall) it sends out 

 long, straight, colorless hyphse, which grow, 

 not only over the Under surface of the leaf, 

 but around the edges and upon the upper sur- 

 face. On the upper surface of the leaves, 

 upon short lateral branches of these hyphae, 

 are borne aggregations of cells, which seem 

 to be characteristic sporodochia of the genus- 

 form ^gerita. These sporodochia are 60 to 

 90 microns in diameter, and are more or less 

 spherical clusters of inflated oval cells, 12 to 

 18 microns in diameter. From near the place 

 of attachment of the sporodochium there 

 radiate 3 to 5 hypha-like appendages, 150 to 

 200 microns long by 6 to 8 microns wide, one 

 to three septate. This entire aggregation of 

 spherical cells and appendages remains in 

 unison, and functions as a spore. When 

 abundant, these sporodochia present to the 

 eye the appearance of a reddish-brown dust 

 over the upper surface of the leaves. If the 

 lower side of a leaf bearing brown fungous 

 stromata happens to be turned upward for 

 some time, the sporodochia will develop abun- 

 dantly there. These sporodochia were first 

 noticed in the fall of 1905, accompanying the 

 " brown fungus " ; but only recently has the 

 connection between the two been proved. 

 Their supposed connection was touched upon 

 in 1908.' 



These sporodochia are curious and inter- 

 esting. When once detached from the leaf, 

 they blow about on smooth surfaces at the 

 least motion of the air, but on alighting upon 

 another leaf or fairly rough paper, they tend 

 to hold fast to it. 



' " Fungi Parasitic upon Aleyrodes dtri," Univ. 

 of Fla., Special Studies, No. 1, p. 36. 



When germinated in hanging-drop cultures 

 these sporodochia produce hsT^hse identical 

 with those of Webber's " brown fungus." 

 When the sporodochia are placed upon the 

 larvse of Aleyrodes cUri, typical stromata of 

 the " brown fungus " arise. During the sum- 

 mer and fall of 1909, sporodochia were care- 

 fully picked off under a compound microscope. 

 A camel's hair brush, moistened with water 

 containing these sporodochia, was drawn over 

 live whitefly larvas. Nine days after, the first 

 and second stage larvse began to show the ef- 

 fects of fungous infection. In sixteen days, 

 initial stages of the stromata were evident 

 bursting through the edges of the larvae. At 

 a later date, the typical brown stromata were 

 formed, and in three months ^gerita sporo- 

 dochia were produced by the surface hyphae on 

 the upper sides of the leaves. 



The economic importance of this fungus 

 makes it desirable that it should have a sci- 

 entific name. The form of the sporodochium 

 most nearly resembles that of the provisional 

 genus ZSgerita. The fungus was referred to 

 Dr. Roland Thaxter, of Harvard University, 

 who kindly examined it, and confirmed the 

 view that it might well be placed under the 

 name of ZJlgerita until the perfect stage was 

 found. It is therefore proposed to designate 

 Webber's ' brown fungus " as ^gerita weh- 

 heri n. sp. The form and appearance of the 

 hyphae suggest relationships to the Hypoch- 

 naceje of the basidiomycetous fungi. 



H. S. Pawcett 



A CORRECTED CLASSIFICATION OF THE 

 EDENTATES 



In a recent paper' the writer was led, from 

 a consideration of various anatomical char- 

 acters, to the recognition of the Edentata as 

 a superorder of mammals comprising four 

 distinct orders, as follows : 



SUPERORDER EDENTATA (Vicq d'Azyr). 

 Order 1. T^niodonta Cope. 

 Order 2. Xenaethea Gill. 



' " A Suggested Classification of Edentates," 

 State University of Oklahoma, Research Bulletin, 

 No. 2, 1909. 



