Sm J. LFBBOCir— PHYTOBIOLOGICAL OBSERTATrOXS. 



371 



same genus, A, arenaria, the smaller cotyledon is reduced to a 

 mere knob (fig. 80 A, ?V). 



Fig. 79. 



Fig, 80. 



Ic 



J^ig. iv. Ce^eiis NapoIco7iis, Section of scerl. oc, outer coat of testa; tc, inner 



coat of testa. 



-*^ig. 80. A, Embryo o? Ahronia arenaria, x 0: {c, smaller cotyledon. B. Em- 

 bryo of A. umfjellata, x : fo, right and inner cotyledon ; Ic^ left 

 cotyledon. 



Cases ill which one of the cotyledons is rudimentary also occur 

 in the genera Ranunculus'^ ^ Qai'umfy Ct/cJamen, &c. 



In Pefiveria octandra (fig. 81) the cotyledons are very interest- 

 ing. The one is about 3 centim. long, 1:^ broad, oblong, tapering 



Fig. 81. 



Fig. 82. 



Fig. 83. 



Fig. 84 



Petiveria octandra. 



Pig. 81. Seedling, half nat. size. Fig. 82. Embrjo partly unfolded, x fu 

 Fig. 83. Outer and shorter cotyledon. Fig. 84. Inner and longer cotyledon 



See Irmisch, *Beit zur rergl Morphol. der Pflanzen ' (Halle, 1854). 

 t Hegelmaier, Yergl. Untersuchungen, 1875. 





