THE EMBRYO 221 



3 



the most complete descriptions. The forms that Ernst include 

 under " pseudo-polyeinbryony " are not treated in our discus- 

 sion of the subject. 



Pseudo-poly embryony . 



1. Ovules Grown Together. Pirns Mains, Loranthus euro- 

 paeus, Viscum album (all A. Braun 4 ). 



2. Division of Nucellus. Morns albus (Hofmeister 2 ). Orchis 

 Mono (Braun 4 ), Gymnadenia conopsea (Strasburger "), Coffea aro- 

 bica ( Hanausek "). 



3. Development of Several Embryo Sacs in the same Nu- 

 cellus. Cheiranthus Cheiri (Schacht 3 ), Rosa sp. (Hofmeister 2 ), 

 Eosa livida (Strasburger "), Tri folium pratense (Jonsson 23 ), Taraxa- 

 cum officinale (Schwere 40 ). 



True Polyembryony. 



A. Embryos derived from cells outside the sac, hence from sporo- 

 phytic tissue (vegetative multiplication or budding). 



1. Embryos Derived from Cells of the Nucellus. Funk in 

 ovata (Strasburger 1 -). Nothoscordon fragrans (Strasburger"), Citrus 

 Aurantium (Strasburger 16 ), Mangifera inclica i Strasburger w ), Euony- 

 mus americanus (Braun 4 ), Coelebogyne ilicifolia (Braun. 4 Stras- 

 burger 16 ), Clusia alba (Goebel"), Opuntia vulgaris (Ganong 49 ), Al- 

 chemilla pastoralis (Murbeck 90 ). 



2. Embryos from Cells of the Integument. Allium odorum 

 (Tretjakow, 36 Hegelmaier 45 ). 



B. Embryos derived from cells within the sac (parthenogenesis 

 and vegetative apogamy) ; although not in the same morphological 

 category, embryos from the suspensor are also included in the list 

 (vegetative multiplication or budding). 



1. Normal Occurrence of Two Eggs. Santalum album and 

 Sinningia Lindleyana (both Strasburger 12 ). 



2. Embryos from Synergids. Glaucium luteum (Hegelmaier 12 ), 

 Mimosa Denhartii and Schrankia uncinata (Guignard 21 ), Iris sibi- 

 rica (Dodel :1 ). Lilium Martagon (Overton 32 ), Vincetoxicum nigrum 

 and V. medium ( Chauveaud 3S ), Allium odorum (Tretjakow, 38 Hegel- 

 maier 45 ). Taraxacum officinale (Schwere 4 "), Aconitum Napellus 

 (Osterwalder 69 ), Alchemilla sericata (Murbeck 90 ), Naias majcr 

 (Guignard M ). 



3. Splitting of Embryo Derived from Egg. Loranthus euro- 

 paeus (Braun *). 



4. Embryos from Antipodal Cells. Allium odorum (Tretja- 

 kow. 38 Hegelmaier 13 ). 



5. Embryos from Endosperm Cells. Balanophora elongata 

 (Treub 48 ). 



