48 



MORPHOLOGY OF ANGIOSPERMS 



subulata, and certain of the Araceae by Campbell 37 - 47 > 4t> ; and 

 there is no doubt that numerous other cases await discovery. 

 It should be remembered also that in many cases of epigyny the 



ovules are probably to be regard- 

 ed as cauline, and if these be 

 added to the cases already indi- 

 cated, it becomes evident that 

 cauline ovules are exceedingly 

 common and occur in all grades 

 of Angiosperms. 



In this connection the curious 

 condition in Loranthaceae and 

 Balanophoraceae may be consid- 

 ered, a condition that may have 

 some connection with their pecul- 

 iar habits. In 1858 Hofmeis- 

 ter 4j 5 studied various species and 

 outlined the prominent feature i 

 of these groups, describing and 



Yio.ll -Balanophoraglobosa A l,nu- illustratinD . geveral stages in tbe 

 cell us with mother-cell of embryo- o o 



sac (shaded) ; the epidermal cells development of the archegomum- 



above the mother-cell give rise to the l^g megasporailgiuill, and also of 

 outgrowth resembling the neckof an endosperm and e mbrVO of 



archegonmm. B, later stage in which l 



the mother-cell has divided into two Balanophoraceae (Fig. 16), and 



cells, both of which "very often de- a ] g0 foe puzzling " lliamelon " ill 

 velop into embryo-sacs": x 166. — T , , , • 



AA / T 4S Loranthaceae. Subsequent mves- 



After Lotsy. 48 1 



tigators have in the main con- 

 firmed and extended this work, the most important modifi- 

 cation being in the interpretation of the embryo; and even 

 here Hofmeister's figures are nearly identical with those 

 of the most recent papers (cf. Fig. 16 with Fig. 107V In 

 1882 Treub 18 described the development of the pistil of 

 Loranthus sphaerocarpus (Fig. 19). A structure (" mame- 

 lon") arises from the bottom of each of the three or four 

 sporangial chambers and grows until it completely fills it, 

 and in this structure hypodermal archesporia appear and 

 develop megaspores in the usual way. It is a fair question 

 whether the " mamelon " is a growth of the axis, whose ovules, 

 represented by separate archesporia, are mechanically hindered 

 from any superficial development; or whether it is an ovule 



