366 ON THE THEORY OF VEGETABLE SPIRALS. 



instance, of the relation of species to the individual, of the whole 

 to its constituent parts, of the unity of type and the endless 

 diversity of forms, we feel that our doubts and difficulties can- 

 not be better expressed than in the words of the old Orphic poet : 



7TW5 e pOl f.V Ti TO, TTO.VT COTCtS, KCU ^COptS Ktt(7TOV J 



Is a cell a unit, or is a leaf, or is a whole plant, or is the idea 

 of unity a relative one, realised in different degrees in lower and 

 higher organisms ? However unsatisfactory this view certainly 

 is, so much must be admitted, that the constituent parts of lower 

 organisms have a greater tendency to commence an independent 

 existence than those of higher : the bond of unity is weaker. 



If, following the train of ideas suggested in the last section, 

 we attempt to express the difference between monocotyledonous 

 and dicotyledonous plants, we may perhaps say that the former 

 assume the condition of independent phyta before they have 

 raised themselves above the system expressed by the number 

 two, or if we look to the leaf alone above the first system, 

 whereas the latter stand one step above them in complexity. 

 And it is interesting to observe that they keep at the same dis- 

 tance throughout, at least, in the greater number of cases three 

 being the prevailing number in the flowers of the former class 

 and five in those of the latter. There is no real spiral structure 

 in what for the sake of regularity we call the spiral |-, because 

 there is nothing to determine which way we are to turn ; growth 

 is in this case an oscillation in a single plane, and the formation 

 of a structure possessing three dimensions must be the result of 

 the superposition of growths in parallel planes. There is no 

 single spiral growth upwards and outwards, binding together 

 indissolubly the growth in both horizontal dimensions ; the 

 primary direction of growth is therefore directly upwards, and 

 any growth upwards and outwards corresponds to another with 

 which it may be said to coalesce, directed outwards and down- 

 wards. Similarly there is no spiral growth downwards and 

 inwards, no tap-root, and therefore in effect no true root at all ; 

 what supplies its place is the downward and outward growth 

 tending to recur at every part of the structure. I do not say 

 that any of this amounts to a demonstration, but it certainly 

 coincides in a remarkable manner with what we know, as a 

 matter of fact, of the growth of monocotyledons, not only with 



