CYSTOPUS. 127 



observed on Gapsella may be summarized here : the fungus 

 attacks all parts above ground, and causes enlargement of 

 parenchymatous cells ; it forms only 

 conidia ; formation of chlorophyll is 

 increased; the formation of interfasci- ^^ 

 cular cambium is diminished or altogether 

 suppressed ; the intrafascicular cambium 

 retains its activity longer; accessory 



vascular hnndlp<! maVp f-.Vipir nnnparnripp • '^'°- 3S— Germinating spores of 

 Vd,l5l.UidI UUUUlbb mdKe tneir appearance , cyttopus portulacae. (After l-ulasne.) 



no differentiation of tissue takes place 



in the ovary wall, the secondary vessels remain incomplete, 



and the embryo dries up. 



C. portulacae, D. C. On Portulaoa oleraeea and P. sativa (U. S. America). 



C. tragfopogonis, Pers.' (C. spinulosus) (Britain and U. S. America). On 

 Compositae, e.g. Chamomilla, Achillea, Cirsium, Scorzonera, etc. The markings 

 •on the spore-coat take the form of a double net-work. 



C. convolvulacearum, Otth. (C ipomoeae-panduraTuie, Farl.). On Con- 

 volvulaceae. (Halsted ^ gives this as one of the causes of rot in sweet potato 

 in America.) 



C. bliti (Biv.-Bern.). On species of Amarantaceae (U. S. America). 



C. lepigoni, de Bary. On Spergularia (Britain). 



Basidiophora. 



The non-septate mycelium inhabits intercellular spaces of 

 living plants, and is nourished by small haustoria. The conidio- 

 phores issue in tufts from the stomata, and have a characteristic 

 form ; they are unbranched with club-shaped ends, from which 

 arise several sterigma-like conidiophores with almost spherical 

 conidia.' The conidia or sporangia are produced in large numbers, 

 and on germination discharge numerous zoospores with two 

 lateral cilia. The oospores are formed singly in the oogonia, and 

 appear as yellowish-brown bodies in the interior of the plant. 



Basidiophora entospora, Eoze and Cornu. On Erigeron cana- 

 dense. Aster, Solidago, etc. (Britain and U. S. America). 



Plasmopara. 



The mycelium is richly branched and grows intercellular, 

 nourished by little button-shaped haustoria. The conidiophores 



'Magnus, Ber. d. deutsch. botan. Ges., 1893. 

 ^ Zeitschrift f. Pflanzenhranhheiten, 1895, p. 338. 



