I9i 2] CURRENT LITERATURE 431 



Although the mitosis in the antheridial cells of Polytrichum agrees in 

 general with that in higher plants, certain peculiarities are pointed out which 

 may prove to be of phylogenetic significance. Such are the delay in the 

 preparation of the nucleus for division until after the formation of the spindle 

 rudiment, the great swelling of the nucleus in one dimension during the pro- 

 phases, the equatorial aggregation of the chromatin following the swelling, 

 and the final shrinkage of the nucleus. It is yet too early to say whether any 

 or all of these features are generally characteristic of mitosis in bryophytes, but 

 many fragmentary observations make this appear quite possible. 



The comprehensive review of cytological work in the bryophytes and the 

 extensive list of literature brought together contribute much toward rendering 

 this paper of the highest value to students of cytology. — Lester \V. Sharp. 



Mallow rust. — In an elaborate paper Eriksson 7 gives the results 

 of many years' investigations on the mallow rust, which, coming originally 

 from South America, has been introduced into Europe, North America, and 

 other countries. The work is replete with experiments and observations 

 covering all phases of the biology and life history of this fungus, which presents 

 peculiar features of interest, first, because in the countries into which it has 

 been introduced it has spread to many plants not native in its original habitat, 

 and second because, being one of the lepto-Uredinales whose teleutospores 

 germinate at maturity, its manner of living from season to season has not 

 been satisfactorily explained. It is in fact this latter phase of the subject 

 which forms the pivot of Eriksson's investigation, and upon which he brings 

 to bear the results of a vast amount of painstaking work. 



The main contentions of Eriksson are that the fungus persists in the 

 seed of infected plants in the form of a mycoplasma, and that it is disseminated 

 chiefly by means of infected seed. The mass of experimental and observa- 

 tional data upon which he bases these contentions are briefly summarized 



here. 



fungu 



— - 



in many places it was first observed on plants grown from seed obtained froni 

 infected nurseries. The fungus is not spread to great distances by means of 

 the sporidia. Wide dissemination is brought about by means of infected 



seeds 



fungu 



In 



grown 



gularly 



This period is required 



for the mycoplasma to change into the filamentous stage and produce spore 

 pustules. The pustules of the primary outbreak are very numerous and are 

 uniformly scattered over the leaves of the young plant, while those of the 



7 Eriksson, J., Der Malvenrost (Puccinia Malvacearum Mont.), seine Ver- 

 breitung, Natur, und Entwickelungsgeschichte. Kungl. Svensk. Vetensk. Handl. 47: 

 5-120. pis. 6. figs. 18. 1911. For summaries previously published by the author 

 see Compt. Rend. 152:1776-1779. 1911, and Centralbl. Bakt. 3* : 93-^5- *9 XI - 



