PEOGRESS OF MICROSCOPICAL SCIENCE. 131 



of Maucliester in 1871.. This is a verticillate strobilus witli a central 

 vascular axis, of wliicli latter transverse sections exhibit a close cor- 

 respondence with the triangular bundle of AsterophyUites, being also 

 triangular, with concave sides and truncate angles. But in order to 

 adapt this primary fibro-vascular bundle to the requirements of the 

 fruit, each of the truncate angles is enlarged, so as to make the entire 

 section an almost hexagonal one. This axis is sm'rounded, as in 

 Asteropliyllites, by a double bark — an outer prosenchymatous one, and 

 an inner one of more delicate cellular structure. At each node this 

 bark expands into a lenticular disk fringed with stiff narrow bracts, 

 which extend upwards and outwards beyond the sj)orangia. The latter 

 rest upon the bractiferous disks and the basal portions of the bracts, 

 each verticil being fertile. The sporangia are closely packed in about 

 three concentric circles, and attached by sporangiophores, originating 

 from each side of the base of each bract. The sporangia have cellular 

 walls ; they are full of large spores, each of which has its surface pro- 

 longed into a number of very long radiating spines. This fruit the 

 author unhesitatingly identifies with the aerial stems previously 

 described. 



He then examines various so-called Volhnannice found in the 

 Lancashire Carboniferous shales, of which the internal structure is 

 not i^reserved, but which, being found with leaves attached to them, 

 admit of no doubt as to their belonging to Asteropliyllites. These are 

 regarded as being identical with Volhnannia Daicsoni ; hence the 

 author accepts the latter fruit as giving the internal organization of 

 the ordinary Asterophyllitean strobilus. The fruit, which has been 

 previously described by Binney, Carruthers, and Schimper, under the 

 names of Calamodendron commune, Volhnannia Binneyi, and Calamos- 

 tachys Binneyana, is then investigated. The above authors had asso- 

 ciated it with Calamifes ; but its internal structure is sho"mi to have 

 nothing in common with that type ; it consists of alternating verticils 

 of barren and fertile appendages. The former are nodal disks bearing 

 protective leaves ; the others are verticils of sporangiophores, usually 

 six in each verticil, and which closely resemble those of the recent 

 EquisetaceaB ; they project at right angles from the central axis, and 

 expand at their outer extremities into shield-like disks, which sustain 

 a circle of sporangia on the inner surface of each shield. The 

 sporangia consist of a very peculiar modification of spiral cells ; they 

 are filled with spores which have been described as provided with 

 elaters, like those of Eqidsetum ; but the author rejects this inter- 

 pretation, regarding the so-called elaters as merely the torn fragments 

 of the ruptured mother-cells in which the true spores have been 

 developed. The vascular axis is shown to be solid, and without any 

 cellular elements, being wholly difterent from that of Calamites, in 

 which the vascular axis is a hollow cylinder containing an immensely 

 large, cellular, and fistular pith. In one fine example of Calamostachys 

 Binneyana the author has found the central fibro-vascular bundle 

 surromided by an exogenous ring. This, too, exhibits no resemblance 

 whatever to the corresponding growths of Calamites ; on the other 

 hand, it corresponds closely with conditions occurring in some parts 



