Jana»ry 21, 1392. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
41 
wide, when the air is dry, for they cannot fliat in still air and in 
wet weather. Thus a whole parish may be infested from a diseased 
allotment plot, and in a brief period the whole country becomes 
infested ; thus dry weather scatters the spores. It does worse, for 
the ground cracks in droughty weather—the badly worked soil, 
least tilth, gaping most ; and the first rain that falls washes the 
conidia and the active zoospores into the soil, among the roots, and 
upon the tubers, and these soon become partly or wholly diseased, 
the fungus having a peculiar penchant for the starch grains concen¬ 
trated in the tubers by the preceding dry weather. That is how 
Potato fungus comes by electric agency in thundery weather. Kain 
concentrates the forces of the fungus on the infecte 1 Potato crops 
—^limits rather than spreads the disease. 
Though the conidia [rather the zoospores], are so potent for 
mischief in warm weather, they cannot live beyond autumn. 
Then the mycelium produces “fruits" instead of conidia. Two 
bodies are produced—one, the oosphere, is globular, the fruit 
proper : the other the antheridium, oval and smaller, and this 
bodv comes to lie against the oosphere, sending into it a^ beak, 
piercing its wall, and fertilising its contents. This production of 
“ fruits ” takes place within the tissues of the diseased plants, the 
oosphere contracting after fertilisation, forming a thick warty outer 
coat, with a thin, elastic, inner lining, and in this protective coat, 
the “ fruit ’’—the oosphere—frost and wet proof, passes the winter 
unchanged. But the oosphere may not always rest, for, when the 
sun has°made the soil warm and the air genial, the globular body 
within the warted coat—like the insect that has passed the winter in 
pupa form—longs to be free, the warmth and the “ soft glow of 
moisture" that prevail in Junetide causes the warty coat to crack, 
and the oosphere rises, floats in dry air, drifts, settles on a Potato 
or Tomato leaf, germinates in a dewdrop, pushes its germinal tube 
through a stomata into the tissues, and reproduces the fungus. 
There are the data upon which the Potato disease must be pre¬ 
vented or combated. 
The sudden appearance of a “mould" on a plant was in 
former days, when observation was not minute and physiological 
research unknown, only intelligible on the hypothesis that the 
plant had in disease given rise to a new form of life—the “ mould. 
Spallanzani first indicated the probability of these living things or 
their germs pre-existing in the atmosphere. Professor Tyndall 
demonstrated that the air does actually contain large quantities of 
minute organic bodies, and this explains why canned fruits keep 
for any number of years, the atmospheric air within its contents 
(crerms producing decay) being excluded. Pasteur showed that 
the pebrine which ruined the silk trade of France by killing the 
caterpillars did not originate within, but was introduced into the 
caterpillar’s body from without—a spore 1-6000th of an inch 
in length, growing, entering the caterpillar, producing and repro¬ 
ducing the disease called pebrine. These spores were named by 
Lebert Panhistophyton. They enter into the eggs of the moth ; 
therefore the disease is contagious, infectious, hereditary. Founded 
on this analogy, it has been suggested that diseases in plants,^ like 
canker in Apple trees and epidemic in Potatoes, may be similarly 
explicable. There is, however, no evidence that plants are liable 
to constitutional diseases that are hereditary and transmissible in a 
manner analogous to the diseases of animals. G. Abbev. 
(To be continued.) 
BRITISH BOTANIC GARDENS. 
An appendix to the “ Kew Bulletin,’ just issued, cont.ains lists of 
the officials in the chief National and University Botanic Gardens in 
Great Britain and Ireland ; it also gives similar particulars with regard 
to the Colonial and Indian Botanic Gardens, The Home list is as 
Rovai Gard ns, A>tr.—Director. W. T. Thiselton Dyer. C.H.G., 
F.R.S., F.L S, Assistant-Director, D. Morris. M.A., F.L ^. Assist.ants 
(Office), John Aikman and J. Bnrtt D.ivy. Keeper of Herbarium and 
Librarv, J. G. Baker. F.R.S.. F.L.S. Principal Assistant. . b. Hemsley, 
F.R.S.;! A.L.S. Mycologist. Dr. M. C. Cooke, M..\., A.L.S. Assi^ants 
(Herbarium), N. E. Brovn, A.L.S.: R Rolfe, A.L.S. : and G H. 
Wright. Assistant for India. Dr. 0. Stapf, Attendant, J. F. Jeffrey. 
Curator of Museums, John K. Jackson, A.L S. Attendant, J, M. Hillier. 
Preparer, George Badderly. Curator of the Gardens, George Nicholson, 
A.L.S. Assistant-Curator. William Watson. Foremen — Arboretum, 
William Truelove ; Herbaceous Department, Daniel Dewar ; Greenhouse 
and Ornamental Department, Frank Garrett ; Tempentte House (Sub¬ 
tropical Department), William J. Bean, 
— University Botanic Garden: Professor. Cffiarles C. 
Babington, F.R S., F.L.S. Secretary to Botanic Garden Syndicate, 
Dr. Francis Darwin. F.R.S., F.L.S. Curator, Richard Irwin 
Curator, Freilerick W. 
Lvnck, A.L.S. 
Dublin—Koj&\ Botanic Gardens, Glasnevin : < 
Moore, Cor. Mom. R.H S. Trinity College Botanic Garvien.s : Professor, 
Dr. E.’Pere^val Wright. F,L.S., Sec. R.I.A. Curator, F. W. Burbidge. 
M.’a., F.L.S. 
Edinburgh .—Royal Botanic Gardens: Regius Keeper. Dr. Isaac 
Bayley Balfour, F.R.S., F.L.S. Curator, Robert Lindsay, F.R.H.S. 
'Glasgow. — Royal Botanic Institution: University Professor, 
Dr. F. 0. Bower, F.R.S., F.L.S. Curator, Robert Bullen, F.R.H.S. 
Oxford. —L'niversity Botanic Garden : Professor, Dr. Sydney H. 
Vines, F.R.S., F.L.S. Curator, William Baker, F.R.H.S. 
Events of the Week. —As noted in another paragraph, the 
National Chrysanthemnm Society have a special social gathering on 
Friday, January 22nd, in Anderton’s Hotel. The annual dinner of the 
Fruiterers’ Company will be he'd on Monday, January 25th, in the 
Hotel Metropole, when the Lord Mayor is expected to take the chair. 
- The Biemingham and Midland Counties Gabdenees’ 
Improvement Association. — The programme of lectures for the 
spring session of 1S92 contains particulars of the silver medal offered 
bv the Journal of Horticulture for an essay on manures, and the 
following announcements ;—January 20th, “ Apples, English, Pro¬ 
duction and Consumption," by Mr. J. Pope ; February 3rd, “ The 
Gloxinia, 1739 to 1S92,’’ by Mr. Jas. Martin of Messrs. Sutton & Sons ; 
Februarv 17th, ‘‘ The Progress of Horticulture in the United States,’’ by 
Mr. A. Outram (Messrs. B. S. Williams A Son) ; March 2nd, “ Modern 
Gardening.’’ by Mr. H. Dunkin ; March 16th, “ The Cultivation of 
Pears in Edgbaston," by F. M. Mole, Esq.; March 30th, “Spring 
j Flowers.’’ by E. J. Baillie, Esq.; and presentation of the silver medal 
' above alluded to. 
i _ The Weathee in the Metropolitan District has been 
j most variable during the past week. On several days sharp frosts 
! were experienced alternating with doll wintry periods. Saturday was 
an exceptionally fine sunny day. 
_ For some weeks the Weather in Scotland has been of a 
I verv wintry character. A snowstorm was general over the whole 
I country, the fall in the northern counties being the heaviest that has 
occurred for several years, leading to the detention of trains, some of 
' which stuck for a day or two in the drifts. In South Perthshire not 
i more than 1.^ inch of snow fell. The frost has been steady, and some- 
i times severe, 15° and 17° having been more than once recorded, 21° on 
one night lately. A cold thaw from E. has taken place.—B. D. 
_ Royal Meteorological Society.—T he annual general 
meeting of this Society will be held at 25, Great George Street, West¬ 
minster, on Wednesday, the 27th instant, at 7.15 P.M., when the report 
of the Council will be read, the election of officers and Council for the 
ensuing year will take place, and the President (Mr. Baldwin Latham, 
M.Inst.C.E.) will deliver an address on “ Evaporation and Condensa¬ 
tion.’’ The above meeting will be prece^led by an ordinary meeting, 
which will commence at 7 p.m. 
_ Reading Gardeners’ Mutual Improvement Associa¬ 
tion.— The following is the programme of lectures for the spring 
session of 1S92 :—February ISth, “ Gardeners and Gardening,” by Mr. 
James Hudson ; February 29th, “ Flowers and Fruit versus Bees.” by 
Mr. H. D. Woodley : March 2Sth, “Germination,” by Mr. F. Tufnail ; 
April 11 th, “The'stephanotis,” by Mr. G. F. Coates, and “Manage¬ 
ment of Smaller Gardens,” by Mr. T. Neve ; April 25th, “ Plant 
Improvement,” by Mr. Lewis Castle. 
_ Mrs. Robinson King Chrysanthemum.—M r. Lawton’s 
remarks on the above Chrysanthemum rather go to confirm than to 
contradict the fact that Mr. Hotham is neither the raiser nor holder of a 
tenth jurt of the true stock. If Mr. Lawton has any confidence in his 
own statement he would substantiate it by offering a premium of £5 at 
the principal shows for every dozen blooms that can be exhibited tNhich 
h.ive been grown and cut from plants that were never in the possession 
of either Messrs, Hotham, Lawton, Blair, or Owen. My object in 
writing this is not to c.ist discredit on any of the above, but as the 
variety is offered by the trade generally it may be only fair to give 
* honour to whom honour is due,” and let the public know the correct 
fjicts—that other vendors have purchased equally true stocks for distr.- 
bution from sources as reliable and equal to those of Mr. Hothiim s. 
A. Jones, ir(jrc*rfrt*<*. 
