Pteridophyten. 309 



Segments of the frond divide and anastomose, and 3—5 ot the 

 adaxial ones enter the spike. It would seem from Campbell's figu- 

 res that in o. moluccanum, 0. lusitanicum and 0. californicum the 



vascular supply is also dcrived from the curved edges of the leaf 

 trace and that in O. intermedium and 0. pendulum the U outlined 

 by the petiolar bundles soon closes and several Strands represen- 

 ting the free edges oi" the trace enter the spike. In 0. (Cheiroglossa) 

 palmatum the vascular supply of one spike arises from both edges 

 of the trace, while that of others arises from one edge only. 



The author holds that in the genus Botrychium the anatomical 

 character of the vascular supply and the frequent presence offertile 

 pinnae upon the sterile segment indicate that the whole leaf was 

 at one time fertile, but that in the course of evolution all the pinnae 

 save the basal pair have become sterilized, while these two have 

 becotne upright and fused, though reversions may oeeur as for 

 example those described in Botrychium obliqiinm. The author also 

 believes that the departure of the Strands and pinnae originally 

 left a gap in the petiolar Strand but that owing to the upright Posi- 

 tion of the spike the departing Strand now adheres to the side of 

 the gap for practically the whole length of the latter. Where the 

 marginal Strand of this genus is incompletel} T developed it is held 

 to be vestigial, the last remains of it being seen in the small pro- 

 minence recorded from B. liinaria. As regards Ophioglossum it 

 would seem that the spikes, to judge from the mode of origin of 

 their vascular supply, may represent a single pinna or two fused 

 pinnae. Finally the author believes that in the highly specialised 

 Helmintostachys a Single pinna funetions as a spike. 



Isabel Browne (London). 



Holden, H. S., On an abnormal spike of Ophioglossum vul- 

 gatum. (Mem. Proc. Manchester Lit. Phil. Soc. LV. 2. 1910—11.) 



The author describes an Ophioglossaceous fertile frond over 

 part of which sporangia are coiled in two spiral bands; there are 

 also two accessory spikes. The origin of the vascular supply seems 

 to show that the strueture has arisen by Chorisis and thus to Sup- 

 port Bower's view that the forms with branched spikes have arisen 

 from forms with simple spikes. At its Insertion on the sterile lobe 

 the vascular supply of the fertile lobe consists of from 3 — 5 bundles; 

 in the normal form these divide to form a maximum of 8 bundles. 

 In the abnormal form just described there were as many as 14. 



Isabel Browne (London). 



Mitchell, G., Contributions towards a Knowledge ofthe 

 Anatomy of the Genus Selaginella, Spr. Part. V. The Stro- 

 bilus. (Ann. Bot. p. 19—33. PI. 3—4. January 1910.) 



Variations are recorded from two species in which the axis 

 grows out vegetatively beyond the cone; another undetermined 

 Indian species shows a gradual transition from fertile to sterile 

 parts. In S. erythropus one branch bore two fertile regions separated 

 by a sterile zone; these cases recall the normal condition of the 

 more primitive Lycopodiaceae. In some species with long crowded 

 cones the middle region is frequently steril in others the basal 

 sporangia do not mature while in S. viridangula they are entirely 

 abortive and the basal sporophylls vegetative in funetion. As regards 

 the distribution of the sporangia there may be a Single large basal 



