•> 



JSLOW ON THE VARIATIONS IN 



EXPLANATION OF THE PLATE. 



Tab. L. 



Fig, 1. Projection of 



j? to the lef 



The arrows indicate the secondary spirals, T % to the right, and 



Obs. Tin' numbers in each figure indicate 

 Fig. 2. This pr jectio i show 



condition 



The dotted lines giv< the true angle (144°) between the first two leaves for this divergence. 



indie 



The** (as also in fig*. 3, 4, 5, 6) show the position of the pair of opposite leaves immediately 



preceding the spiral arrangements. 



Fig. 



method of chancre from 



5 



Pig. 4. Illustrat 



Tins u effected, as also shown in fig. 2, by a convergence of two leaves to one side ; but the 

 angle at the centre between them is less than in the case of a change to the divergence f . 



or yt approximately. 



bein 



riderable distance above the 1st, it is somewhat difficult to say which divergence might 



represent most nearly the generating spiral. 



I ; i£. r». Illustration of a change. 



into 



turning 



i terminating with the 9th leaf; secondly, from 1 

 is re\ . is right-handed, and belongs to the divergence f . 



The thickeD I portions of the spiral between the Nos. 8 and 9, 14 and 

 21, signify that the leaves corresponding to those pairs of numbers 

 the expanded base of their petioles. (The same occurs in figs. 6, 7, 8 



Fie. 6. 



his diagram illustrates a case wn< 



hare < averged to one side. Thei 



of their petioles remain confluent, 

 three being on the same horizon 



the**. The bases 



(N 



occurs five times 



the true spiral arrangement of the divergence f is eliminated by the development 



internodes. 



be 



! 



No. 2. Hence, if the one to the right be taken 

 t will be No. 8 ; and the arrangement must be 

 t be chosen as No. 2. then the same leaf imme- 



No. 9 : and this arrangement must 



3. 



Obs. 2. In some cases the ultimate 



or two leaves united and on< 



terruptt dry to the summit of the stem. 



Pig. 7. Plain-am 



The 



are 



(divergent and still coherent. 



as 



internodes, and, the spiral 



become entirely free by the development 



int< i 



o 



uninterruptedly 



Tl 



spiral arrangement f to , 

 The next cycle belongs 



es commence 



base of the stem) with 



by the 9th leaf being 



oil 



