chap, in The Morphology of the Flower 107 



ment of the embryo in Monocotyledons was given by 

 Hanstein in 1869, in his account of his researches on 

 Alisma. He was confirmed by Famintzin in 1879. 

 A somewhat different type was described in 1874 as seen 

 in Pistia ; it is remarkable for the absence of a suspensor. 

 A third form, which is characteristic of many of the 

 Orchidaceae, was investigated in 1879 by Treub. It is 

 remarkable for the development of the suspensor into 

 a haustorial organ. Yet a fourth type was found to exist 

 in many of the Liliaceae in 1894 by Coulter, characterized 

 by the irregularity of its segmentation, and by the develop- 

 ment of a massive suspensor. 



The exact nature of the so-called cotyledon of this 

 embryo has been disputed. Solms-Laubach showed in 1878 

 that in certain cases its origin is lateral, and the apex of 

 the stem terminal. Other variations in embryos of the 

 Alisma type were noted by Campbell at the end of the 

 century. The normally terminal position of the cotyledon 

 and its physiological function as an absorbing organ were 

 suggested by Bayley Balfour to show that its true homo- 

 logies should be looked for in the foot of the Pteridophytic 

 embryo. 



For our knowledge of the Dicotyledonous embryo we 

 are again indebted to the researches of Hanstein in 1869, 

 and those of Famintzin ten years later. The form first 

 investigated was Capsella, which has maintained its position 

 as a kind of standard or typical embryo, though many 

 small varieties in the details of development were noticed 

 during the later years of the century. Guignard showed 

 that a different type exists among the Leguminosae, nearly 

 forty species of which he examined. The chief feature 

 they present is the extremely massive suspensor, which 

 in some species is coenocytic in structure. Guignard's 

 researches were published in 1881. In some of the 

 Mimoseae and Hedysareae he observed another variation, 



