394 DIVISION IIL-—MODE OF LIFE OF THE FUNGI. 
Later there follows also a penetration of the Fungus into and between the dead and 
dying cells of the deeper-lying tissue-layers !. 
In connection with this subject it will be well to recall the fact, that the hyphae 
of certain Fungi which are parasitic on other Fungi unite with those of the host, and 
the two protoplasmic bodies enter into continuity and 
coalesce by disappearance of the cell-membrane in such 
a manner that there is no longer a clear distinction 
between host and parasite. The fact has been ob- 
served in Chaetocladium and has been described 
above; it probably occurs in other cases also, for ex- 
ample in Artotrogus*. The obscure and disputed 
phenomena observed in Nyctalis and some other like 
cases may perhaps find their explanation in a similar 
relation between the two plants. 
Section CXIII. The effect which endophytic 
and epiphytic plant-parasites exercise on their 
host, when they do not at once put an end to its life, is 
seen in a richly graduated series of phenomena, from 
the slow exhaustion and wasting away of the host to 
the characteristic transformations which in extreme 
cases even promote the health and growth of the host, 
and which take place when certain parasites attack plants 
that are sufficiently young and capable of growth. 
Examples of the first kind are to be found on all sides 
and may be studied in pathological and descriptive 
treatises. The first indication of a hypertrophic 
transformation may be said to be given by the fact 
to which Cornu® has called attention, that spots on 
leaves and fruits occupied by such Fungi as Erysiphe 
Fic. 166. Species of Saprokgmi.  Suttata (Aceris), Cladosporium dendriticum and the 
Extremity of a tube attacked and de’ Tjredineae have a more abundant and more persistent 
formed by Rozella septigena. The x 
upper part is divided by transverse walls. supply of chlorophyll than their neighbours which are 
into seven sporangia of Rozella, six of 
which 2 are empty, some showing the 1 
vote inthe lateral walwherethecore, ‘free from the Fungus. Next to this comes the normal 
escaped; the lowest zx is still full of 1 im] 7 1 
Sore’? Further down the tube hee accumulation of products of assimilation in cells at- 
wich coetain each me tacked by a Fungus which has been already noticed 
a ater Coma ig in a former page, and lastly the mycetogenetic growth 
hat, Sr. 5, XV. ph 6). Magn. about of the cells themselves and of the tissues which they 
compose. For the hypertrophies and transformations 
proceeding from the latter cause, so far as they occur in Phanerogams, it is sufficient 
to refer to the examples adduced on page 368 and in earlier chapters. We may 
however add to them in this place the description of the peculiar transformations 
produced in the Saprolegnieae by certain Chytridieae, and especially the one which 
results in the formation of the plant-form described as a Lichen. 



1 See Bot. Ztg. 1874, and R. Göthe, Ueber d. schwarzen Brenner u. d. Grind d. Reben. Leipzig 1878, 
? Bot. Ztg. 1881, p. 575. 3 Comptes rend. 93 (1881). 
