FLORA OF THE CARBONIFEROUS EPOCH. 61 



the leaves connected with the fructification. The fmit- 

 bearing leaves are stalked, peltate, and are arranged in 

 whorls of 6. There are four sporangia borne on the under- 

 surface of the peltate leaves. These spore- cases have cellular 

 parietes, and in their interior there is a deposit of cellulose 

 in the fonn of short truncate processes not unlike imperfect 

 spirals. The spores are spherical, and appear to have thread- 

 like processes proceeding from them, similar to elaters. The 

 fruit-cone bears a marked resemblance to the fruit of Equi- 

 setum in its fiiiit-bearing leaves, sporangia, spores, and 

 elaters (see Figs. 18, 19, 20, 21). In the modem plant all 

 the leaves of the cone are fructiferous, while in the fossil 

 plant some are fruit-bearing, and others are like the ordinary 

 leaves of the plant. It is thought that the fossil may be 

 reckoned as having a somewhat higher position than that pos- 

 sessed by the living genus. 



The different forms of foliage called Asterophyllites, 

 Sphenophyllum, and Annularia, belong to the one genus 

 Calamites, but they may form, perhaps, well-characterised 

 sections when their fruits are better known. In woodcut 48 

 representations are given of the foliage and fruit of varieties 

 of Calamites. In 1 and 2 we see the simplest form called 

 Asterophyllites. The leaves are linear and slender, with a 

 single rib. The form called Annularia (3 and 4) differs chiefly 

 in having a larger amount of cellular tissue spread out on 

 either side of the midrib. This form has a different aspect 

 in a fossil state from the other, from its whorls of numerous 

 broad leaves spread out on the surface of deposition, while 

 the acicular leaves of Asterophyllites have penetrated the soft 

 mud, and are generally preserved in the position they origin- 

 ally occupied in reference to the supporting branch. The 

 third form (5 and 6) is called Sphenophyllum, and consists of 

 whorls of wedge-shaped leaves, with one or more bifurcating 

 veins. They occur like those of Annularia, spread out on the 

 surface of the shale. 



