518 PROFESSOR DICKSON ON SOME ABNORMAL CONES OF PINUS PINASTER. 



vinced of the futility of the endeavour to derive the different forms from one 

 origin. Indeed, we seem almost compelled to recognise both the ordinary simple 

 spiral and the ordinary bijugate as fundamental forms, i.e., forms with either 

 of which a cone may commence without the intervention of another ; and if this 

 be done, the derivation of the various systems from the one or from the other 

 would be a very simple matter. 



Before concluding, I would submit a tabular analysis of the five flower- 

 spikes of Banksia occidentalis, already brought under the notice of the Society, 

 but which may very profitably be reconsidered in connection with the above 

 communication . 



Tabular Analysis of five flower-spikes of Banksia occidentalis in Museum of Economic Botany, 



Royal Botanic Garden, Edinburgh. 



One, with — — — 7 7 14 



2x7 

 Two „ — 1 6 7 13= ^ 



One „ 1 2 5 7 12=1 



5_ 

 13 



One „ 1 2 3 5 8 13 = 1 



I shall not stop to inquire from what one or more fundamental forms these 

 may be derived, but it is very interesting to note how, among these forms, we have 

 spirals of the most widely different fundamental divergences, closely resembling 

 each other in the number of their secondary spirals and verticals, just as we 

 have seen above in the case of the fir cones. 



It is possible that, in ignorance, I have gone over ground which has been 

 trodden before; for example, I have not had access to any of Schimper's 

 works on phyllotaxis. However, as it is in the highest degree improbable that 

 the abnormal forms above described should repeat themselves, I rest assured 

 in the belief that I have contributed at least new, if not valuable matter. 



In conclusion, I would specially thank my friend Professor Tait for the 

 many valuable suggestions I have received from him in the course of this 

 work, and for his patience and readiness in assisting me when in any 

 difficulty. 



