252 
the leaves and the reappearance of the fungus the next year, during 
which time other sorts of spores are probably produced to finally 
carry the disease to the new crop of lettuce; but all attempts at fol- 
lowing the course of development have so far proved unsuccessful. 
Passerini described the species in 1879,* but had already published 
the name with specimens found in 1878.+ It was also found in the 
autumn of 1879 by Saccardo,{ and is undoubtedly common through- 
out Italy. Ido not find it mentioned by German, French or En- 
glish writers. It isrepresented by a specimen in Ellis’ North Amer- 
ican Fungi (No. 345), collected at Newfield, N. J., also in 1879, 
and was found in the same year by Dr. Forbes, in Jllinois, and inde- 
pendently described by Peck as 8, Lactuce,§ but is not named in 
any local lists of the United States. This indicates that the fungus 
has only recently become sufficiently abundant to attract attention, or 
that it is recently introduced into this country. 
The fungus usually shows as black or brown specks on the green 
surface of the leaf, as already described, but occasionally the leaf be- 
comes dead and dry in irregular spots of a half inch or less in diame- 
ter on which the specks are more conspicuous. ‘This form has re- 
ceived a separate name, Septoria consimilis EH. & M.|| and appears to 
be the form that Peck’s description] applies to. It will, undoubt- 
edly, be found to be merely an incidental condition, but is not, how- 
ever, mentioned by the Italian observers. At any rate there is no 
essential economic difference in the two forms, and the technical 
difference may be left to the systematists. 
lt is not clear what can be done to prevent the spread of this dis- 
ease. The fungus being an internal grower, nothing can stop its 
progress in the plant after once gaining a foothold, but the extermi- 
nation of the plant itself. To test the effect, if any, of topical apphi- 
cations, a row of (Green Fat) lettuce was thoroughly sprinkled on 
July 15 with a saturated solution (one part in eighteen hundred) of 
salicylic acid, and the next row to it with a portion of the same dilu- 
ted one half. No apparent effect of any sort was produced, either 
upon the lettuce or the fungus. A row of (Green Dutch) lettuce 
was sprinkled at the same time with a saturated (10 per ct.) solution 
of borax. When the water had evaporated, fine crystals of borax 
remained in piaces on the leaves. No effect appeared to follow fora 
time, but after awhile the lettuce was completely killed, and pre- 
sumably the fungus with it, although the fungus was certainly not 
killed in advance of the leaf supporting it. If it is necessary to em- 
phasize the fact that external applications are in general nearly or 
quite useless on internal parasites these experiments will carry some 
weight. 

*Fung. Parm. in Atti Soc. Critt. Ital., II, p. 35. 
+Erb. Critt. Ital., II, 746, and also Myc. Univers., No. 1295. 
tMichelia, I, p. 527; II, p. 278. § Bot. Gazette, IV (June, 1879), p. 170. 
|| Jour. Mycology, I, p. 100. TAs 

