ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 423 



fore likely to vary according to varying conditions to a much greater 

 extent than other characters less dependent on existing circumstances, 

 and more fixed in the long course of descent. 



The species are grouped in two divisions : Tenuisquam^e, with thin 

 cone-scales ; and Crassisquam^e, where the cone-scales are notably 

 thickened towards the apex and are more woody than in the preceding 

 group. Division I. includes two sections : Strobus, with resin-canals, 

 marginal, and seeds winged ; and Cembra, with resin-canals median, and 

 seeds nearly or quite wingless. Division II. contains eight sections- 

 which fall into two sets, one in which the bud-scales are deciduous, 

 loosely imbricate and membranous, the other in which they are per- 

 sistent and coriaceous. The sections are differentiated by the number 

 of leaves in a tuft, the shape of the leaf and of the meristele in section, 

 the entire or serrulate margin, and the marginal or median resin-canal. 

 Nearly eighty species are enumerated. 



Morphological Peculiarities of the Nymphaeacese and Helobise.* 

 J. H. Schaffner discusses the position of Nymphaeacege in a natural 

 system of classification, basing his remarks partly on the result of a, 

 recent study of various species. He refers to the well-known mono- 

 cotyledonous character of the vascular bundles of the Nymphseaceae, 

 which are of the " closed " type. The bundles of the flower stem 

 of Nelumbo closely resemble the grass type. Of superficial characters, 

 the similarity of habitat, the rhizome habit, the striking agreement of 

 some of the leaf-forms, and the general character of the flowers suggest 

 a relationship with the Helobife. A precis is given of the results of 

 the study of a few representative species of Naiadales and Nymphasaceae ; 

 " it is certainly much easier, 1 ' says the writer, " to read Monocotyl 

 characters into the flowers than Dicotyl." Thus, if we regard the so- 

 called petals of Nymphma advena as staminodes, the perianth becomes 

 typically trimerous with three sepals and three petals. In Castalia 

 there are sometimes four petals, but in C. odorata there are normally 

 three in a cycle, but sometimes by the expansion of the receptacle one 

 of the segments of the second cycle is partly or nearly completely 

 brought to the outside. This tendency of the floral organs to fall into 

 sets of four is seen in Potamogeton and other Helobiae. The transition 

 from comparatively simple flowers to those with great numbers of parts, 

 as appears in passing from Cabomba to Nijmplma is also characteristic 

 of the Alismaceae ; the extreme numbers doubtless represent multi- 

 plication or augmentation. The superficial placentation of Butomus 

 and Vallisneria finds a parallel in Nymphcm and Castalia. Coalescence 

 and epigyny also occur in both groups. 



Lyon's investigation of the embryo of Nehimbo suggested a mono- 

 cotyl type, and the affinity of Nynrphaeaceas with the Helobiae. Cook 

 also found that in the young embryo of Nymplum the cotyledon is at 

 first not lobed ; later there is a rapid development at the two sides, 

 resulting in a two-lobed structure. The writer finds that the embryo 

 of Castalia odorata must be regarded as of the same type as Nijmplwa 

 and Nelumbo. He compares the embryo of the Nymphaeaceae with the 



* Ohio Naturalist, iv. (1004) pp. 83-92, (3 pis. and 2 figs, in text). 



