160 
As a proof of how much there is still to be learnt respecting the life history 
of Agarics, I may say that in Sach’s recently published Z’ewt Book of Botany, one 
of the very best and most complete books of its class ever published, there is no 
mention whatever made of cystidia in the description of Agaricus, and in La Maout 
and Decaisne’s Descriptive and Analytical Botany, under fungi, it is stated that 
the male organs never produce antherozoids, and that the cystidia are always 
deprived of sterigmata or spicules. 
To repeat and follow out these observations it is necessary to take the 
specimens for examination exactly at the proper period of growth, and to exercise 
the greatest care in securing an uniform moisture between the glasses. The life of 
the fungus is so short, and all the characters are so evanescent that the points to 
be observed may be present one moment and all gone the next, 
All the drawings have been made with a camera-lucida, and from different 
specimens, so where the dimensions of the parts slightly disagree, it is only such 
a disagreement (within defined limits) as is commonly found in Nature. 
THE POTATO FUNGUS. 
Mr. Worthington G. Smith, F.L.S., also exhibited his drawings illustrating 
the resting-spores and life history of the Potato Fungus, the Peronospora infestans, 
and though he did not read a paper, made remarks to the following effect, though 
there is here incorporated some results not obtained till the ensuing spring, and 
published in the Gardeners’ Chronicle :— 
T last July obtained the oospores or resting-spores by keeping Potato leaves 
and tubers continually moist. For many years past moisture has been well known 
to be capable of greatly exciting the growth of Peronospora infestans, and De Bary 
in his recent essay classes the Potato fungus (p. 242), with ‘‘ other water fungi.” 
Mr. C. Edmund Broome of Batheaston, who is known as one of the first crypto- 
gamic botanists of this country, repeated my experiments in the following manner: 
He selected potato leaves badly infected with Peronospora, partly crushed them, 
and placed them in a saucer of water under a bell-glass. The saucer was kept in 
asloping position, so that the leaves (being partly submerged) were allowed to 
absorb the water naturally. The result was that he obtained an enormous number 
of resting-spores in all parts of the leaves, many being within the spiral vessels 
and hairs. These resting-spores were in every way identical with mine, and they 
could only belong to the Peronosporee or Saprolegniez, because similar bodies are 
unknown in other families of fungi. The first-named family has jointed threads, 
the second bears threads without joints ; now as the threads seen by me, and last 
year illustrated-in connection with the resting-spores, had jointed threads, they 
must belong to Peronospora, and not to Saprolegnia. As there is no other 
