The principles of biology . then in the Sycamore and the Viae, we have a cleft type ofleaf in ?which a decided hUateralness of forqa co-exists witha decided hUateralness of conditions. The quite simple leaves to which we now descend, exhibit,very distinctly, a parallel series of facts. Where they growup on long and completely-independent foot-stalks, withoutdefinite subordination to some central vertical axis, theleaves of water-plants are symjnetrically peltate. Of thisthe sacred Indian-bean, Fig. 216, furnishes an example. Herethere is only a trace of bilateralness in the venation of theleaf
The principles of biology . then in the Sycamore and the Viae, we have a cleft type ofleaf in ?which a decided hUateralness of forqa co-exists witha decided hUateralness of conditions. The quite simple leaves to which we now descend, exhibit,very distinctly, a parallel series of facts. Where they growup on long and completely-independent foot-stalks, withoutdefinite subordination to some central vertical axis, theleaves of water-plants are symjnetrically peltate. Of thisthe sacred Indian-bean, Fig. 216, furnishes an example. Herethere is only a trace of bilateralness in the venation of theleaf, corresponding to thevery small difference of the con-ditions on the proximal and distal sides. In the Victoriaregia, Fig. 217, the foot-stalks, though radiating almosthorizontally from a centre, are so long as to keep the leavesquite remote from one another; and in it each leaf is almostsymmetrically peltate, with a bilateralness indicated only bya seam over the line of the foot-stalk. The leaves of theNymphaa, Fig. 218
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectbiology, bookyear1864
