256 PLANTS OF NEW ZEALAND 



Hoheria angustifolia, Plagianthus hetidinus) the intermediate 

 form, in its compact scrubby habit, and small leaves, bears 

 a remarkable resemblance to certain Coprosmas. In other 

 examples, the intermediate form, though not of the type of a 

 Coprosnia (e.g. Fseudopanax) , is simpler than either the first 

 or third stages, which often resemble each other. These 

 remarkable differences between the appearance of New Zealand 

 plants in their earlier and later stages, have puzzled botanists 

 very much. They seem to be but little known outside of our 

 islands. Thus, Dr. Cockayne states : — " On this point I can 

 speak with some authority, since during the past few years, 

 I have personally raised from seed thousands of species of 

 extra-tropical plants, and in few, save certain Australian 

 genera and Conifers, have I noticed any marked change in 

 leaf to take place."* 



The Law of Eecapitulation. 



Now it is generally believed that the same law of develop- 

 ment holds in the plant world as in the animal world, i.e.^ 

 that the individual in its development goes through, in order, 

 the same stages that its ancestors have gone through, in their 

 development. Thus, in the mammalian embryo, a fish stage 

 and a reptihan stage are clearly to be recognized. However,, 

 this law must not be interpreted too literally, and in 

 considering any special example, large allowances have to be 

 made for the effect of environment, and for unknown factors. 

 We cannot, therefore, reason backwards from embryonic to 

 ancestral life, with any assurance of accuracy. However, the 

 law is broadly true, and of considerable biological value. 

 Now evolution, — unless accompanied by degeneration, — 

 usually proceeds from the simple to the complex. But,. 



* Trans., Vol. XXXI. p. 356. 



