144 
VARIABILITY OF SPHAERIA QUERCUUM, SZ. 
found in all the different forms, but as yet not in asci. They occur 
but sparingly it is true, but a careful and patient search is sure to 
reveal their presence. I wish here to amend my original state- 
ment so far as the colour of the sporidia is concerned. In all 
fresh specimens examined, the sporidia are hyaline. Some speci- 
mens on Quercus alba and on Vaccinium Pennsylvanicum, both of 
which had been poisoned, have brown sporidia, but as the colour 
may be due to the action of the poison, it will be safer to assume 
that the sporidia are hyaline till the examination of fresh and 
living specimens shall show them to be brown. 
It is asked why twenty other specimens having similar sporidia 
were excluded from the list ? Simply because I had not actually 
examined specimens of these species, and it was not intended to 
give mere opinion, but to state facts actually observed. As to 
“ ignoring all variations of internal structure ” and “ discarding all 
external features,” I am willing to let the specimens speak for 
themselves.* 
* I intended to add to the original paper a foot note, designating all the 
forms with perithecia not nnited in a stroma var . simplex , but as no other 
additions could be made after the article was in type, I was obliged to 
content myself with adding this note with pen and ink to the copies sent me 
for distribution. ( Reprinted from Proc. Acad. Soc., Phil.) 
Note to the above. — I have printed this 11 reply ” in fairness 
to the writer, but I do not purpose to continue the controversy, 
which, in common with others of a similar nature, would only tend 
to foster ill-feeling, and be of no interest to the public at large. 
Mr. Ellis has an undoubted right to the opinions he has professed, 
and a foregone conclusion would not be shaken by any evidence 
which I might offer. The type specimens are still in my posses- 
sion, as well as original preparations of the fructification, and 
analytical drawings of all the species, so-called. In time these 
will find a place in some public institution, where they may be con- 
sulted by all concerned in the subject. I am quite content to wait 
and abide by the verdict of unbiassed judgment. My opinion 
rests upon the identical specimens which I have examined, and on 
no others. I much regret any difference of opinion between myself 
and Mr. Ellis ; and as this difference relates to species publishedin 
our joint names (in many instances), but which Mr. Ellis thought 
fit to impugn, it became my duty to accept his judgment as publicly 
as he had made his criticisms, or, if I could not do this, to utter my 
protest. The latter course is the one which I followed, and with 
that I am now content to abide. Controversies of this kind are 
interminable, great consumers of time, and seldom profitable to 
any one. It is with no disrespect to Mr. Ellis that I decline his 
challenge, but I find time all too short for working purposes to be 
wasted in fruitless discussion. 
M. C. Cooke. 
