224 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



B. CBYPTOGAMIA. 



Cryptogamia Vascularia. 



Development of Sporangia.* — K. Goebel continues his researclies 

 into the comparative history of development of the sporangia of the 

 higher cryptogams.f These are all characterized by the presence of 

 an " archespore." 



The Marattiaceas were examined chiefly in the example of Angio- 

 pieris evecta. The sporangia are developed from a group of superficial 

 cells, on the receptacle formed by the superficial cells of the depression 

 of the sorus, corresponding to the placenta of phanerogams. Here 

 also it is the hypodermal terminal cell of the axial row of cells of 

 the rudiment of the sj^orangium that gives rise to the whole of the 

 s2:)orogenous tissue. By the formation of anticlinal and j^ericliual 

 walls in the cell above the archespore, it becomes 3ubsequeutly im- 

 bedded in the interior of the tissue. The Tapetenzellen arise from 

 the cells which bound the archespore. Marattia cicutcefolia and alata 

 agree in all essential points. 



In OpMoglossum it is probable that the sporogenous tissue also 

 proceeds from either a hypodennal or a superficial cell. Cells are 

 produced by periclinal divisions of the parietal cells, which very 

 soon become compressed, and which may also by analogy be termed 

 Tapetenzellen. The processes are very similar in Botrychium and 

 Anemia. 



The investigations on Equisetum do not confirm Milde's view that 

 the sporangia are produced on the surface of leaves. The apical cell 

 of the sporangial fructification becomes, on the contrary, soon enclosed 

 in a small-celled tissue. 



The author enters with considerable detail into the development 

 of the sporangia of the Psiloteae, especially Psilotum and Tmesipteris. 

 He agrees on the whole with the view of Sachs and Strasburger that 

 the sporangia are here not the product of the leaves, but are more or 

 less imbedded in the tissue of short lateral axes. The Psilotese are, 

 therefore, widely sejjarated from the Lycopodiaceae by this difference 

 in structure. 



In Selaginella the sporangia arise from superficial cells of the 

 vegetative apex of the stem, which lie immediately above those from 

 which the apex of the leaf proceeds. The archespore is again the 

 hypodermal terminal cell of the axial row. The radially elongated 

 cells which clothe the inner surface of mature sporangia may be 

 regarded as Tapetenzellen. The outermost of them are given off by 

 the archesjDore ; while those near the pedicel are separated from the 

 adjacent cells. 



The morphological value of the sporangia of the Archegoniatae, 

 therefore, varies greatly. 



The author then compares the development of the sporangia of the 

 higher cryptogams with that of the pollen-sacs or microsporangia of 



* Bot. Ztg., xxxix. (1S81) pp. OSl-94; 697-706; 713-20 (1 p].). 

 t See this Journal, iii. (1880) p. 987. 



