240 The Ottawa Naturalist. [Feb. 



nudicaule, Aconituni Anthora , Leontice vesicaria, tuberous species 

 of Oxalis, Megarrhiza Californica, species of Smyrnhim, Buniimi 

 luteum, ChcErophylluni hulhosum (but not Ch. procuinhens), 

 Dodecatheon, species of Polygonum, and Rheum, and one 

 of the Composites, namely Serratula radiata. However, as stated 

 by Miss Sargant, short petiolar tubes are not uncommon among 

 the seedlings of species allied to those enumerated above, for 

 instance: Ranunculus millefoliatus, Ferula fcetida, Serratula 

 tinctoria, Rheum officinale, etc.; these link the numerous species, 

 in which the cotyledons are merely connate at the base, with 

 those in which the cotyledonary tube is fully developed, and 

 their existence is a strong argument for the derivation of such 

 tubes from the fusion of two cotyledons. 



i\s the last type of seedlings with epigeic cotyledons may be 

 mentioned the so-called Pseudo-monocotyledones. Characteristic 

 of these is the development of only one of the two cotyledons, the 

 other one being completely suppressed. Members of this type 

 are Claytonia Virginica L. (Fig. 33), Erigenia btdbosa Nutt. 

 (Fig. 32) and Dicentra Cucidlaria D.C. To these may be added, 

 according to Miss Sargant: Corydalis solida, C. cava, C. fabacea, 

 Carum btdbocastanum, Cyclamen persicuni and Pinguicula 

 vulgaris. In Erigenia the primary root soon commences to in- 

 crease in thickness so as to form a round, tuberous bod}^ and 

 the single cotyledon, which consists of a long petiole and a simple, 

 green blade is the only leaf that appears above ground during 

 the first year. Claytonia Virginica genninates in the same way, 

 but in this a leaf may appear in the first season, alternating with 

 "the cotyledon, and with the base partly surrounded by the 

 sheath of this. Dicentra Cuctdlaria is described by Irmisch, 

 and the cotyledon of this species possesses a blade with three 

 very distinct divisions, a structure which otherwise is xevy 

 seldom met with in cotyledons; it is the more peculiar since the 

 blade of the cotyledon in the species of Corydalis is entire. It 

 seems to be characteristic of these Pseudo-monocotyledones , w-ith 

 the exception of Pinguicula, that the subterranean organs 

 (base of petiole, hypocotyl, or root) are more or less tuberous. 



In passing now to describe some types of seedlings in which 

 the cotyledons are hypogeic, I wish to state that even if this 

 manner of germinating be very distinct from the one in which 

 these leaves are epigeic, there are, nevertheless, some plants 

 which exhibit a kind of transition between both. For instance, 

 if we compare the cotyledons of Phaseolus mdgaris, which at first 

 are hypogeic, but later on become epigeic and green, with those 

 of Phaseolus multiflorus, which are hypogeic and pale, but turn 

 green, when artificially exposed to the sunlight. 



