PERISPORIACE^. 383 



191), which constitutes the earpogonium, and which is soon 

 divided by cross-partitions into several cells. Prom below 

 the spiral there pushes out a branch (the antlieridium), which 

 grows upward, and brings its apex in contact with the upper 

 cells of the earpogonium {B, Fig. 191). After this pro- 

 cess, which constitutes fertilization, other branches grow up 

 around the earpogonium, and finally completely enclose it, 

 as in the parasitic genera described above (C, D, E, and F, 

 Fig. 191). By the subsequent growth and division of the 

 enveloping branches, the earpogonium becomes imbedded in 

 a thick parenchymatous mass. In the meantime, from the 

 cells of the earpogonium branches bud out and penetrate the 

 surrounding parenchyma {F, Fig. 191), and finally produce 

 eight-spored asci on their extremities {G, Fig. 191) ; after a 

 time the asci are dissolved, and the sporocarp, now of a sul- 

 phur-yellow color, contains only loose ascospores, intermingled 

 with the debris of the broken-up asci and parenchyma.* 



The plants of this order are abundant and easily studied. The 

 following partial list will enable the student to intelligently begin his 

 investigations : 



Parasitic Plants. 



A. Perithecium containing a single ascus. 



Appendages floccose Genus, SpJicBrotheca. 



Appendages diohotomous " Podosphcera. 



B. Perithecinm containing many asci. 



Appendages needle-shaped, rigid Genus, Phyllactinia. 



Appendages hooked " Uiieiimla. 



Appendages dichotomoQS " Microsphmra. 



Appendages floccose " Erysi/phe. 



Sphmrotheca pannosa occurs on wild gooseberries, on wliose stems, 

 leaves, and fruits it forms brown felted masses. In its conidial stage 

 it is frequently so abundant on the leaves of roses as to entirely destroy 

 them. 



S. Gastagnei sometimes occurs upon the hop in such abundance as to 

 destroy the crop. 



* The student is referred to De Bary's " Morphologic und Phyaiolo- 

 gie der Pilze," etc., 1865, p. 162. A translation of the part relating tq 

 the ErywpTiei appeared in " Grevillea," Vol. I., p. 158. 



