GENERAL RESULTS— LYCOPSIDA 633 



phoric," bearing their sporangia on specialised append- 

 ages, whereas throughout the Lycopods we find a 

 single sporangium seated directly on the sporophyll, 

 or in its axil. This simple arrangement may also be 

 due to reduction ; the ventral outgrowth of the sporo- 

 phyll which bears the sporangium in Spencerites has 

 been compared to the sporangiophore of Spheno- 

 phyllales, and Miss Benson has recently interpreted 

 the sterile tissue of the sporangium in Mazocarpon and 

 an allied fructification as representing a sporangiophore. 

 These suggestions are very interesting, but at present 

 too hypothetical for any conclusion as to affinity to be 

 based on them. 1 



In the anatomy there is no doubt a considerable 

 analogy between the Lycopods, especially the Palseozoic 

 types, and the Sphenophyllales. The stelar structure 

 of Cheirostrobus, for example, is much like that of a 

 Lepidodendron such as L. selaginoides, allowing for the 

 fact that the leaf-arrangement is verticillate in the one 

 and spiral in the other. This type of stele, 2 however, 

 may also occur in Ferns (though not characteristic of 

 that class) ; its wide distribution is one of the facts 

 in favour of an ultimate common origin for all the 

 vascular phyla. On the whole it appears probable 

 that some remote affinity really exists between the 

 Lycopods and the Sphenopsida, but probably no closer 

 than that between the Sphenopsida and the Ferns. 



The Lycopods manifestly attained their highest 

 development in Palaeozoic times, as regards abundance, 



1 See also Miss M. G. Sykes, "Notes on the Morphology of the 

 Sporangium-bearing Organs of the Lycopodiaceae," New Phytologist, vol. 

 vii. 1908, p. 41. 



2 i.e. an exarch protostele. 



