DICHOCARPISM 



on short sporophores ; but, mixed with these, later on appeared 

 the perithecia and ascospores of a compound Sphaeria, an 

 Ascomycete. In the fifth we had a Mucor producing spores 

 in terminal sacs, and, by conjugation of other branches, 

 zygospores. In the sixth a Peronospora with terminal 

 zoosporangia on branched hyphae, and oospores upon the 

 mycelium. Lastly, a mould, bearing conidia on the branches, 

 and afterwards from the same mycelium a Mucor with inflated 

 terminal sacs enclosing spores. All these are examples of a 

 second form of fruit produced from the mycelium of the first. 



We have now to indicate briefly those species which are 

 reputed to possess two forms of fruit, the genetic connection of 

 which has not yet been clearly demonstrated. It may be 

 premised that there are a large number of cases in which an 

 association of this kind has been suspected, but it is needless 

 to cite more than two or three. In the summer the leaves of 

 Bumex are often marked on the under surface with mealy 

 white spots, seated upon discolored blotches of the green 

 leaves. These spots are caused by a white mould with a short 

 and simple, rarely branched conidiophore, supporting at the 

 apex a single elliptical conidium, attached obliquely; this is 

 Ovularia obliqua. In the autumn the same plant, and often 

 the same leaves, will present similar spots, which do not carry 

 the mould but clusters of very minute perithecia, half immersed 

 in the leaf. These perithecia contain cylindrical asci, each 

 enclosing eight oblong uniseptate sporidia. It is supposed, 

 and with some good show of reason, that the mould constitutes 

 the conidia of this Sphaerella rumicis, but the connection does 

 not appear to have been definitely established. "We have 

 observed the two on the same leaf, but not on the same spot. 



The leaves of horse-radish (Armoracia) are often seen 

 covered with whitish circular blotches, upon which are 

 sprinkled a number of minute black dots, the partially im- 

 mersed perithecia of a species of Phyllosticta, having minute 

 sporules on slender sporophores. Later in the year similar 

 spots on leaves of the same plant are occupied with perithecia 

 of almost identical appearance, but containing the asci, hitherto 

 immature, of a supposed Sphaerella armoraciae. There is no 

 evidence of the relations subsisting between the two Fungi, 



