SECTIONAL TRANSACTIONS.— K. 411 



Further, we find an articulate plant, Calamophyton primcevum, with triangular 

 xylem, finely cut whorled leaves on the smaller branches, and lax, cone-like fructifica- 

 tions. 



Similar fructifications also occur in Hyenia elegans, nearly related to the 

 H. sphenophylloides of Nathorst, and, like that, \vithout any clear nodal articulations. 

 The two genera are regarded as representatives of two series, Hyeniales and Calamophy- 

 tales, and are placed before the true Articulatae, as Proto-articulatse. Possibly 

 another, hitherto undescribed, plant-form from Elberfeld may likewise belong here. 



Hyenia may be regarded as a small, xerophytic shrub. The same applies to 

 Gladoxylon scoparium, the first species of the group in which the foliage and sporo- 

 phylls are now known. The systematic position of the Cladoxylese is still doubtful. 



Finally, the last land-plant is of the habit of a tree-fern. But the ramifications of 

 the large pinnse show the anatomical structure of an axial organ — namely, a xylem - 

 body consisting of reticulately pitted tracheides, with narrow medullary rays. 



Only the nerveless ultimate pinnules can be interpreted as foliar organs. The 

 sporangia of the fertile branch-systems may be considered as terminal. Aneurophylon 

 germanicum stands near to Eospermatopteris, Goldring. Further forms belonging 

 here are Spiropteris, Sphenopteris condrasorum, and Gephalotheca mirabilis. Whether 

 we are dealing with primitive seed-plants is still an open question, as is also the con- 

 jectural near relation to Palceopitys. 



The flora of Elberfeld has both geological and botanical significance. The 

 Psilophytales, including Asteroxylon, render possible a connection of the microphyllous 

 plants with the mosses. Forms like Hornea and Anlhoceros stand near one another. 

 They suggest the hypothesis that the leaf has here originated as an epidermal emer- 

 gence. Aneurophyion also possesses loaves of that nature. On the other hand, the 

 leaf of a true fern (and hence also, no doubt, of the seed-plants, except perhaps the 

 Coniferae) is to be compared with the whole pinnate branch-system of Aneurophylon. 



The flora of the Middle Devonian already enables us to recognise at least two 

 distinct developmental series for the higher plants. For the present it may remain 

 undecided whether these series go back to a common stock. The flora consists of 

 quite distinct, highly organised types, which are mingled with representatives of the 

 Psilophytales. It shows similarities with the Middle Devonian flora of Scotland, 

 Norway, and Bohemia. 



26a. Prof. R. J. Harvey-Gibson, C.B.E., and Miss D. Milner-Brown. 



Fertilisation in Bryophyta. Polytrichum commune. (Preliminary 

 Note.) 



From the researches of PfeSer, Buller, Lidfors, and others it has long been known 

 that sperms are attracted to the archegonia of Pteridophyta by malic acid or other 

 chemotactic substance, that sugar is the attractive body in Musci and a proteid in 

 Hepaticse, provided that the living sperms are brought into the vichiity of the open 

 necks of the archegonia ; but, so far as we are aware, there is no record of how the 

 sperms, in the first instance, reach the archegonia. As the result of prolonged observa- 

 tions on Polytrichum commune during spring and summer of the present year, we have 

 established the following facts : — 



(1) Both the male and the female ' heads ' are constantly visited by mites belong- 

 ing to the group Oribatidae, two species of ' spring tails ' (CoUembola), a small midge 

 (Diptera), a larval form of one of the ' leaf hoppers ' (Cicadidae). an Aphis, both 

 winged and apterous forms, and a spider. (For the identification of these insects, &c. , 

 we are indebted to Prof. R. Newstead, F.R.S., who has examined them in situ.) 



(2) Contrary to our original expectation, we found that the paraphyses contained 

 no sugar but mucilage only. The mucilage was abundantly exuded, especially from 

 the spathulate paraphyses on the male ' head,' but also as well from the filiform 

 paraphvses round the archegonia. 



(3) The visiting insects greedily lap this mucilage, while at the same time their 

 bodies, legs, mouth parts, and antennae become smeared with the excretion. They also 

 lick at the saline crystals formed on the perichaetial leaf-margins. They even pierce 

 the antheridia themselves, for in some instances their intestines were found to be full 

 of chlorophyll grains. The mucilage on their bodies contains large numbers of sperms, 

 actively motile. In cases where the anthoridial walls have been pierced, manifestly 

 the apical dehiscing apparatus of the antheridium is unnecessary. 



