68i 



SCIENCE. 



[Vol.. II., Xo. -12. 



A strange sassafras-leaf. 



The obsei-Aations upon the sassafras-leaves — a re- 

 port of which appeared in Science, no. 36 — have 

 been continued tlirough the year, with results which 

 do not differ materially from those already given. 

 Three other forms, however, have been found, which 

 are given in the accompanying outline-engravings. 

 Fig. 1 shows a peculiar modification of the three- 

 lobed form, and differs from it in having the main 

 central lobe reduced to a slightly raised emarginate 

 end to the leaf. At first sight it seemed as if the leaf 

 had lost its middle lobe by some foraging animal; but 

 the absence of any roughness in the outline, and other 

 characteristics of the edges, preclude this view. The 

 form shown in fig. 2 helps to confirm the above view. 

 In this we have a three-lobed form, with the lateral 

 lobes unequal, and the central and upper portions of 



ner in which this has been accomplished is simple, 

 and is fully shown by the outline given. The middle 

 lobe has become lobed upon one side, — a 'thumb' 

 has formed; and, were the lower portion of the leaf 

 removed, it would leave a 'mitten' of good shape. 

 The whole framework of the leaf has become some- 

 what distorted: the mid-rib does not take a direct 



the leaf inverted heart-shaped (obcordate). The mid- 

 rib has stopped short, and divided into two equal 

 parts, which run to the tips of the two diverging 

 lobes. If this failure of the mid-rib to extend had 

 taken place earlier, a leaf might have been produced 

 similar to the one shown in fig. 1. 



The most interesting of the three new forms is 

 shown in fig. 3. Here we have a happy combination 

 of the three-lobed and the ' mitten' form. The man- 



course; and the lower lobes are neither equal, nor at 

 the same distance from the base of the leaf. 



It is due the reader to state that these three forms 

 were all found upon the same shrub, — not a large 

 one, — and that only a single specimen of each was 

 discovered. These were all upon the same branch, 

 though scattered among fifty or so of leaves of the 

 three forms before described, and which, fi'om their 

 uniform presence, may be considered normal. How 



