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INTRODUCTION TO CYTOLOGY 



Apogamy.- The cases to be considered under this head may be 

 arranged in two groups: 



1. Pseudapogamy: sexual act abnormal. — The following abnormalities 

 have been observed: 



(a) Fusion of two female organs: observed (Christman 1905) in 

 certain Uredineae (Caoma nitens, Phragmidium speciosum, 

 Uromyces Caladii) where adjacent archicarps fuse: male cells 

 (spermatia) are present but functionless. 

 (6) Fusion between nuclei of the same female organ: observed in the 

 ascogonium of certain ascomycetes, Humaria granulata (Black- 



Fig. 124. — Apogamy in ferns. 



A, nuclear migration in gametophyte cells of Lastrcea pseudo-mas var. poly dactyl a. 



X 500. {After Fanner and Digby, 1907.) B, section through gametophyte, showing 



young sporophytic tissue (s) "engrafted" into surrounding gametophytic tissue (g). 



(After Farmer and Digby.) C, sporophyte arising apogamously from gametophyte in 



Pier is cretica: b 1 , first leaf; v, stem apex; w, root. (After de Bary.) 



man 1906), where there is no male organ; Lachnea stercorea 

 (Fraser 1907), where the male organ (pollinodium) is present 

 but apparently functionless. [A similar condition has been 

 reported in Ascobolus furfuraceus (Welsford 1907), Aspergillus 

 repens (Dale 1909), and Ascophanus carneus (Cutting 1909).] 

 (c) Fusion of a female organ with an adjacent tissue-cell: observed 

 (Blackman 19046) [Blackman and Fraser 1906] in the archicarp 

 of some Uredineae (Phragmidium violaceum, Uromyces Pow, 

 Puccinia Poarum) : male cells (spermatia) present but function- 

 less. 



