Tubiflorcc. 
30 .? 
tolerably sure that the carpel-number is at any rate greater than 
two. But a four-, six- or ten-locular ovary may be tbe product of 
two, three or five carpels. The Boraginaceae offer a familiar example 
of this ; in these the number of carpels is known to be two, typically, 
but tbe ovary is divided into four uniovulate compartments. The 
general biological significance of this phenomenon is not altogether 
obvious, but it may be suggested that, broadly speaking, it is 
connected with fruit and seed-dispersal, and its occurrence in any 
group may be regarded as at least an attempt in the direction of an 
efficient mechanism to that end. 
The whole question is but one aspect of the broad general 
problem of the detailed structure of the ovary and its significance; 
and as this becomes a matter of increasing importance in the 
consideration of these higher groups, it will be well to take the 
present opportunity to discuss it at length. The closed ovary is 
the essence of the Angiosperm, and its primary object is ovule- 
protection. But this protection must not be afforded at the expense 
of efficient seed-dispersal; hence various devices have been evoked 
in the course of descent which are aimed to secure the latter end, 
the protective function at the same time being exercised as long as 
possible in the career of the seeds. The end in view is the conveyance 
of the seed to a spot suitable for its germination and for the 
subsequent development of the plant-body ; that is to say, a greater 
or less distance has to be covered. The host of different types of 
fruit, with their varied mechanisms for dehiscence, dispersal, and 
so on, are all referable to this function of conveying the seed to a 
distance. In some cases evolutionary effort, if we may so express 
it, has been directed chiefly to the rapid dispersal of the individual 
seeds, which become independent of the fruit soon after maturity ; 
such is the case with the cornose seeds in the multiseminate follicles 
of Apocynaceae and Asclepiadaceae. But the general trend of 
descent in this regard seems to have been tbe combination of efficient 
dispersal with an extended period of protection, and this has been 
secured in the obviously most adequate way by the association of a 
single seed with a fruit-body. This in turn has been effected in 
various ways, all of which seem to fall under one or another of the 
following heads:—first, the apocarpous pistil, which, in the primitive 
form typified in Ranales, entails a considerable expenditure of 
material for each individual flower and so has been abandoned in 
the course of evolution in obedience to the principle of economy: 
second, the schizocarp, under which head the Boraginaceae fall: 
and third, the unilocular fruit containing a single seed, the product 
