33 



CALAMARIEAE. 



matter partly on the structure of the wood in the axis of the spikes, partly 

 on the details observed in the spores, in which he is persuaded that he sees 

 an interior cell-formation resembling that in the pollen-grain of Cordaitae. 

 He appeals also to the combination of the grains into tetrads, comparing 

 them with the tetrads in the pollen of Angiosperms, and lastly to the cir- 

 cumstance that tetrads of perfectly similar character are found in the 

 pollen-chamber of certain Trigonocarpae and of Gnetopsis trigona. He 

 considers that the leaves of the sterile whorls were coherent in Arthropitys 

 and free in Calamodendron. The following sentence is characteristic ' : 

 ' In Calamodendron, Arthropitys, Annularia and some species of Astero- 

 phyllites the fructifications are disposed in almost the same manner, that 

 is to say, in the form of spikes composed of sterile and fertile whorls 

 alternately ; in most cases it is not possible to determine from the im- 

 pressions the precise nature of the reproductive bodies belonging to these 

 groups of plants, which are however somewhat remote from one another.' 

 It is not easy to criticise so dogmatic a statement, especially when the 

 grounds for it are all put before us in so brief and prefatory a manner ; 

 but I would make the following observation. We have no analogue any- 

 where of a male flower with alternating fertile and sterile whorls of leaves. 

 That single spore-tetrads are found in the pollen-chamber of wind-fertilised 

 Gymnosperms is not conclusive; every cell which is smaller than the orifice 

 of the micropyle will find its way into it, if it reaches it in its flight. Spores 

 connected together in fours are not known indeed, but are perfectly possible. 

 The interior cell-formation can also prove nothing, if we suppose it to be a 

 rudimentary prothallium, as I do notwithstanding Strasburger's recent 

 arguments ; it is peculiar, as we know, to microspores, and the degree of 

 development is of no importance. Lastly, what will Renault do with 

 Williamson's spikes which contain macrospores and microspores? These 

 must necessarily remain with Annulariae in spite of their resemblance to 

 Calamostachys Binneyana. The sole criterion therefore remaining is the 

 secondary wood of the axis of the spikes, and with this we arrive once more 

 at the petitio principii of Brongniart's school so often mentioned already, 

 which makes the understanding of their writings everywhere so difficult. 



Lastly we may unite with Calamostachys Grand' Euryi certain fructi- 

 fications which Weiss 2 names C. tuberculata (Fig. 45 B], while he makes 

 the genus Stachannularia previously 3 created for them into a subdivision. 

 Renault and Grand' Eury 4 especially are inclined to regard the two as 

 directly synonymous, and they may be right, though as the states of pre- 

 servation are not comparable we cannot at present have positive proof in 

 either direction. Unlike the spikes hitherto described which are all petri- 



Renault (17). 3 Weiss (5). 3 Weiss (6). * Grand' Eury (1), p. 45. 



