15 



cuter the inicr()p\k', and siil)sc(iiiciitl)- the ovule Jevclopes so as to 

 fill the ovarian cavitv. The aborted ()\ule is retained at the smn- 

 mit of the ca\it\-, its fuiiieulus iie\er dexelopini,', and its niicropyle 

 out of" reaeh of the pollcn-tuhes, even if its nucellar structures 

 were developed to iecei\e tiiem. 



To i-eeur now to the niatuie seed, it will he found to consist 

 niaiidy of a much developed embryo-sac, filled with endosperm 

 and a small embryo. The embryo-sac never entirely replaces the 

 nucellus, more or less of the nucellar tissues being found on the 

 commissural side, either pressed a<2^ainst the flat or concave face of 

 the embryo-sac or cir.liraced in its infolding-. I mportant charac- 

 ters have been obtained frt)ni the comniissuial face of the seed, 

 based upon the fact that !t may be convex, plane, concave, or more 

 or less involute. Great care should be exercised, however, to 

 obtain seed of perfect maturity, or a compaiison f)n this basis will 

 amount to nothins:. All seeds at i^rst ha\e a convex or plane fiice, 

 and the amount of concavity or infolding will depend upon the de- 

 velopment of the embryo-sac. In some coses the embryo-sac, in- 

 stead of devf^loping uniformly, developes strongly towards the 

 commissure on the two sides, resulting in a concave or involute 

 seed-face. This variation may occur in the mature fruits of a single 

 spet:ies (as in Euhp/ins), so that there may be found plane or con- 

 cave sccd-faccs in one and the same plant. 



Characters used in classification. — By far the most im- 

 portant characters are obtained tVom the fruit. The three scries of 

 Bentham and Hooker, based upon simple anil compound umbels 

 and oil-tubes, we ha\e not found tenaV>le. I'he compounding of 

 umbels is too irregular in some genera to determine their proper 

 position, and in the first series, with "tvVAr ad valleculas o," San- 

 iciila and Eryngium both have oil-tubes. We have therefore 

 divided our UmbcllifcriC into two series, based upon the develop- 

 meiit of secondary ribs or not, which giouj)ing practically merges 

 Bentham and Hooker's first and second series. Our second series, 

 which is by far the larger, v.e iiave broken into groups based upon 

 the flattening of the fruit, which seems to be a \ ery reliable char- 

 acter, and one which best groups together related genera. Char- 

 acters which arc used in further subdivisions, enumerated in the 

 Older of their general importance, are as follows: flattening of the 



