272 МВ. В. &. ADAMSON ON THE COMPARATIVE ANATOMY 
Subgenus II. EvvERONICA. 
V. loganitoides. E. 
V. linifolia. C. 
V. eatarracte. 
V. Lyallü. F. 
V. Вай. 
In the above table there are certain striking disagreements ; perhaps the 
most striking is that of V. loganioides occurring in a different subgenus from 
the forms apparently allied to it anatomically. Cheeseman remarks that this 
is a plant of dubious affinity *, in that florally it approaches tho herbaceous 
section of the genus, while vegetatively it is almost inseparable from some of 
the allies of V. lycopodioides. 
Huchedé + arranged an anatomical table for the species he examined, 
based mainly on the arrangements of the bundles, especially in the petioles 
and leaf-base. This character was taken as being the one least altered 
in response to external conditions. This arrangement follows the Floristic 
Classification given above in the main ; the chief exception is the separation 
of V. Traversii from its apparent allies to near V. cupressoides, owing to its 
having three bundles at the base of the petiole, unlike most of the other 
New Zealand species. He shows an interesting parallelism between the 
modifications of the New Zealand species and those of the Northern 
Hemisphere. He regards this analogy as the result of the effect of parallel 
conditions on pri mitively different species. This conclusion is further borne 
out by the close structural analogies between species of Veronica with plants 
of entirely different affinities. The most striking are those of the highly 
modified species, or © whip-cord ? Veronicas ; thus, V. tetragona was originally 
described as a species of Podocarpus under the name of “ P. Dieffenbachü " |. 
Externally it is very like a large-leafed form of Podocarpus cupressinus, but 
structurally there are great differences. In leaf-stucture it is very similar to 
Lycopodium quadrangulare, in which species the epidermis is similarly 
modified, though not nearly to the same extent. Again, both in form and 
structure there is great similarity between V. cupressoides and Cupressus 
sempervirens, Where the xerophilous adaptations of the epidermis, stomata, 
and mesophyll are very similar. Some species of Crassula, e. g. С. lyco- 
podioides, show a strong external resemblance to some of the * whip-cord ” 
Veronicas, and bear much the same relation to other species of the genus ; 
but in leaf-structure there is always great difference between the two 
genera. Numerous other examples might be cited, showing a parallelism of 
* Cheeseman (1906). + Huchedé (1907). 
t Cf. Goebel (1908). 
