138 MORPHOLOGY. 



made with a magneto-electric spiral* are a mere jest, and a very superfi- 

 cial one, since we have not as yet obtained any proof, based upon the most 

 remote appearance of probability, of the presence of a galvanic current, 

 for which there is not even a semblance of possibility when we consider 

 the damp, and consequently universally conducting, condition of the cell- 

 membranes. 



77. We have, as yet, no general numerical laws for plants. 

 Indications of such admit, perhaps, of being traced from the fact 

 that, in the far greater majority of cases, two, four, or eight young 

 cells are formed within the parent-cell, as in Tetraspora, in the 

 spores of the Octosporidia, Mosses, and the pollen of Phanerogamic^ 

 To these we may probably also add the frequently regular occur- 

 rence of definite numbers in whorls, as the recurrence of the number 

 three in the parts of the flower of the monocotyledons, and the 

 number five in the dicotyledons. 



All these specified relations have already often been used in mere 

 childish numerical jugglery ; individual cases having been arbitrarily 

 selected to confirm a preconceived theory, the exceptions being disre- 

 garded, fashioned by means of just as arbitrarily imagined fictions into a 

 form adapted to the pretended theory. We cannot as yet decide, even 

 with the most remote approximation to probability, if, for instance, the 

 three petals of a monocotyledonous plant are to be regarded as a triple 

 whorl or as a three-limbed spiral. These two must, however, be very 

 differently derived from the nature of the plant, and, in the latter view, 

 the contest originating in the hitherto equally balanced hypotheses of 

 Schimper and Bravais would still remain to be decided. Before we can 

 give any probability to such a deduction drawn from the nature of the 

 vegetable organism, it is at any rate but just, amid the large number of 

 exceptions present before us, to consider the more frequent occurrence of 

 one or other number as purely accidental to plants in general. This 

 occurrence of the numbers 2, 4, 8 in the young cells seems to possess 

 more the appearance of systematic arrangement, but here we are utterly 

 unable to discover any connection with the nature of the vegetable cell. 

 We shall probably have to wait long before we meet with even indications 

 more definite. 



CHAPTER II. 



SPECIAL MORPHOLOGY. 



78. THE history of development forms the groundwork for 

 all special botanical morphology, and we must, therefore, have 

 reference to it in choosing our general modes of classification. 

 Every plant originates from a cell ; and the first difference among 



* As, for instance, in Link's Element. Phil. Bot. ed. 2. t. i. p. 1^7. 



