SPORE-PRODUCING MEMBERS 



It remains no\v to consider the morphological character of the sporangio- 

 phore in the Equisetales. The current view of the strobilus of Ei/itixc/um 

 is that it is a product of meta- 

 morphosis of the sterile shoot, 

 and that the sporangiophore 

 is an altered sterile leaf. This 

 has been re-stated lately by 

 Goebel, 1 on the basis of de- 

 velopment of the individual, 

 but without bringing the fossil 

 Calamarian strobili into the 

 comparison. It may, however, 

 be safely asserted that if Equise- 

 tum and Equisetites had never 

 existed, a comparison of the 

 Calamarian strobili with those 

 of other Pteridophytes would 

 have led to a different view ; 

 it will be necessary therefore 

 to examine this natural group 

 of the Equisetales as a whole, 

 and not only one isolated genus, 

 even though that type be the 

 well-known one now living. 



Taking first the developmental evidence derived from Equisetum, as 



SP 



Equisctnin limosum, L. .Median longitudinal section of a 

 sporangium at the base of the strobilus, together with the 

 annulus (a). X 200. 



k 



. >-' 



ftr: 



j&)~> < ,> 



< ,fM , 





^Jf^^CfZ r 



S 5 ^' 2&L ^ 







Fu;. 210. 



Calatnostachys Ctishc m,i. Tangential section, showing four sporangia grouped around 

 their sporangiophore (j^>). Three contain megaspores and one microspon . X3o. Phil. 

 Trims. II'. ami S. //"///. Coil., 1587. (From Scott. S/m/ifs in Fossil Botain . ) 



given by Goebel,- it is found that, notwithstanding the difference in mature 

 form (which Goebel notes, and from which he concludes that the distinction 



1 Organography, vol. ii., pp. 499-503. -/..<-., p. 500. 



