98 CYCADEAE, MEDULLOSEAE. 



development of the female flowers from resting buds of the old stem cannot 

 mislead us, for this circumstance, as is well known, recurs constantly as 

 a biological adaptation at very various points in the vegetable kingdom. 

 These conclusions enable us to dismiss Nathorst's l view, who, if I rightly 

 understand him in his paper, which unfortunately is only to be read in the 

 Swedish, compares Bennettites with the Balanophoreae, and especially with 

 Lophophytum, and considers it to be a parasite of the stem of a Cycad. 

 Saporta -, on the other hand, questions the facts of the case, and passes 

 over the genus with the following words : ' The following tribe, that of 

 the Bennettiteae, is if possible still more strange, since according to 

 Mr. Carruthers it -had enclosed fruits situated inside the enlarged bases 

 of the petioles. In spite of the apparent precision with which the details 

 of the anatomical structure are figured by the English botanist, it is 

 difficult to admit the reality of such organic combinations.' Renault 3 also 

 seems to have been led astray by this and omits the genus altogether. 

 A fertile shoot petrified in carbonate of iron and probably belonging 

 to this group has been recently found in the Oxfordian beds of the 

 Vaches noires in Normandy by Moriere, and has been described by 

 Saporta and Marion 4 as the fructification of Williamsonia Morierei, Sap. 

 et Mar. ; its resemblance to the fructifications of Bennettites seems to 

 have escaped these writers. 



Carruthers includes also in his genus a few other stems of similar 

 elliptic form on the transverse section. First of all Bennettites Peachianus, 

 Carr. 5 from the Lower Oolite of Helmsdale in Sutherlandshire. The speci- 

 men in the Botanical Department of the British Museum, which is not 

 well preserved externally, shows the whorled transverse sections of the 

 lateral axes of the inflorescence, and must therefore belong to Bennettites. 

 A small number of rings of secondary wood are developed in the pith 

 in a similar manner to that which will have to be noticed hereafter as 

 characteristic of the Medullosae. Bennettites maximus, Carr., of which no 

 figure is given, also belongs certainly to the group. I have satisfied myself 

 of the presence of the lateral fertile shoots by examination of the original 

 specimen in the Jermyn Street Museum in London. Both this species and 

 B. Saxbyanus come from the Wealden formation of the Isle of Wight ; 

 B. Saxbyanus also shows the lateral shoots, and its ring of wood is exactly 

 like that of B. Gibsonianus. In a specimen, which is classed by Carruthers 7 

 with the above forms and is split longitudinally, it can be seen that the 

 leaf-traces, of which numerous horseshoe-shaped transverse sections are 

 found in the outer rind, run direct and in straight lines in an obliquely 

 ascending direction from the ring of wood to the leaves. They do not 



1 Nathorst (5). 2 de Saporta (4), vol. ii, p. 53. 3 Renault (2). 4 Saporta et Marion 



(2), p. 244. 5 Carruthers (4), t. 62. Carruthers (4'j, t. 57. 7 Carruthers (4), t. 57, f. 4. 



