202 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The authors point out in conclusion, that the probability of the 

 modification of vascular structure at the node of the plant — in relation to 

 an alteration of the leaf -trace — and the effect of leaf -traces in modifying 

 stem-structures generally, has been noted in one form or another by 

 nearly all recent writers on vascular morphology. The principle of the 

 decurrency of such a new structure from the node into the internode 

 below, and its eventual establishment throughout the internode, to join 

 a similar structure at the next node below, is evidently one of very wide 

 application in the Filicinean series. The particular instance of it 

 described in the present paper is of special interest, since it brings before 

 us a mode of origin of an internal system of rhizomic vascular strands, 

 differing from that described by Gwynne-Vaughan in a number of types. 

 Whereas the internal ridges and strands in Dicksonia, Ct/athea and Pteris 

 elata arise at the node as a local thickening of the leaf-gap, those of the 

 plants here described arise as lateral elaborations of the leaf -trace itself. 



Germinating Spores in a Fossil Fern.*— D. H. Scott figures 

 a section of a fern-sporangium cut from a nodule obtained from the 

 Halifax Hard Bed. In the multiseriate structure of its wall, the 

 sporangium resembles those of the Eusporangiate Ferns ; there is also 

 evidence of the existence of an area of enlarged cells, comparable to the 

 group which discharges the functions of an annulus in the Osmundaceae. 

 This accords with the close agreement pointed out by Bower between 

 certain carboniferous sporangia and those of this recent family. 



The sporangium contains a considerable number of spores, approxi- 

 mately spherical in shape, many of which had begun to germinate 

 within the sporangium. Several of the latter are figured, and show a 

 close agreement with the stages of germination in recent fern-spores. 

 The author refers to germination of spores as being not uncommon in 

 recent Ferns when effectual dehiscence has been hindered, and remarks 

 on the interest of his observations — as showing that some at least of the 

 Carboniferous Ferns followed the same course of development as their 

 recent allies. The agreement with corresponding stages in the develop- 

 ment of fern-prothalli at the present day, leaves little doubt that in this 

 Carboniferous Fern also the spores produced the sexual generation in the 

 way familiar to us. It is uncertain to what Fern the sporangium be- 

 longed ; a frond of the Sphenopteris type occurred in the same prepara- 

 tion, but there is no evidence to connect it with the sporangium. 



Two Megasporangia in Selaginella.j — F. M. Lyon figures a longi- 

 tudinal section of a megasporophyll of SelagineUa rupestris, showing two 

 sporangia in nearly median longitudinal section. They are not placed 

 side by side, as in the Lycopodium described by Bower, but as if the 

 additional sporangium was developed in the line connecting the normal 

 megasporangium with the ligule. The figure also shows the normal 

 reduction of the megaspores to one or two, so common in SelagineUa 

 rupestris. 



Ferns of the Philippines.^ — L. M. Underwood publishes a summary 

 of our present knowledge of the ferns of the Philippines, giving an 



* New Phytolog., iii. (1904) pp. 18-23 (2 figs.). 



t Bot. Gazette, xxxyi. (1903) p. 308 (1 fig.). 



j Bull. Torrey Bot. Club, xxx. (1903) pp. 665-683. 



