1902] CURRENT LITERATURE 311 



r 



% 



\ 

 I 

 ) 



downward in the latter, and the stem bears many small, crippled leaves. 

 Nematodes were found to be the cause of the trouble. Recently the same 

 disease has again appeared near Alexandria. Microscopic examinations 

 showed that the nematodes were more abundant in the secondary roots than 

 in the main ones. The secondary roots are destroyed, the food supply is thus 

 cut off and the growth is checked in consequence. The matter is complicated 

 by the presence of other species of nematodes. ** Trap-crops " are suggested 

 for the removal of most of the nematodes. This it is argued will remove so 

 many that they will not be especially injurious. No other definite remedy is 

 given. — P. Spaulding. 



NOTES FOR STUDENTS. 



P. J. O'Gara,^ of the University of Nebraska, has conducted experi- 

 ments which indicate that Sphaeropsis r/wina of the sumac and S. maloruM 

 of the apple are the same fungus. At least, the former will cause black rot 

 in the fruit of the apple, and will also produce the typical " canker " on the 

 branches just as readily as the latter.^ — J, M. C. 



Mrs. E. G. Brixton and Miss A, Taylor 5 have published an account of 

 the morphology and anatomy of Vittaria lineata. The prothallium is irreg- 

 ularly branched and consists of a single plate of cells. It has remarkable 

 powers of vegetative propagation and produces gemmae very similar to 

 those described by Goebel for V, elo?tgaia. The antheridia are very 

 numerous, and are produced either upon the ventral surface of the pro- 

 thallium or upon the gemmae, and rarely upon the same prothallium as the 

 archegonia. The development of the antheridium is of the usual polypod 

 type, with funnelform wall and cap cell, and twelve or twenty-four sperms 

 are produced. The long stalk of the sporangium seems to be formed chiefly 

 by a single row of three or more elongated cells, longitudinal divisions 

 occurring next to the spore-case. The interesting observation is made that 

 the small stalk-cells at the base of the spore-case become very much inflated, 

 and when the case opens they tilt it back. Long-stalked, branching, and 

 multicellular paraphyses occur among the sporangia, the terminal cells being 

 elongated, curved, and enlarged at apex. — J. M. C. 



Items of taxonomic interest are as follows : Spencer LeiM. Moore 



(Jour. Bot. 40 : 305. pi. 441. 1902) has described a new African genus {Affipho- 

 ranihns) of Caesalpineae from Damaraland. — E. L. Greene (Pittonia 5 : i- 

 56. 1 902) has published 6 new species of Acer, 22 new species of Microseris, 

 14 new species of Phacelia, 7 new segregates of Viola canadensis^ 8 new 

 acaulescent violets, a revision of Romanzoffia (10 species, 8 of which are 



^Science 15 : 434-435. 1902. 



5 The life history of Vittaria lifteata. Memoirs Torr. Bot. Club 8 : 185-211.//?. 



I 



