Apeil 6, 1912.] 



THE GARDENERS' CHRONICLE. 



215 



7 feet 6 inches at 2 feet from the ground. I am good library, and collected many valuable pic- 

 aware that there are taller Douglas Firs in the tures, but the whole was destroyed by fire 24 

 country, but what surprises one is to see such years later, causing loss estimated at '£70.000. 

 ponderous growth rising up from such poor, Colonel Johnes built the present mansion, ' s*nd 

 shaly substance. Perhaps the isupply of water in the course of six years is said to have planted 



THE NATURE OF PARASITIC FUNGI. 



THEIR INFLUENCE UPON THE HOST 



PLANT. 



(Concluded from p. 19S.) 



, i i A i j j x £ xi n ., . , « ' Our next problem to consider is the mode of 



channel along the roadside most of the year will, mg sod earned up the mountain side to place a Hfe of fun / and their influence upon the host 



which trickles down the mountain sides into the 



000 



few handfuls round the young trees. For many 



000 



in a measure, account for such results. 

 Emerging into the open, clumps of healthy 



plants of choice Rhododendrons on the fringe annually, beside planting hundreds of acres with 

 of the mountain facing south are passed, with Acorns. The trees now extend some miles on the 

 some choice Conifers not many years planted. mountain side, bordering on the roadway at the 

 Passing through a gateway, there is to the west back of the mansion. They are not scrubs, as 

 -a winding carriage road across a park-like en- 

 closure, terminating in a roadway that passes 

 the back of the mansion, leading to the main 

 road, where there is another lodge entrance, 

 about two miles distant. The carriage-way is 

 known as the Duke's Drive, as it was made, 

 about 70 years ago, by one of the Dukes of 

 Newcastle, who purchased the property, and, 

 four years later, after spending a large sum of 

 money on the estate, sold it. It changed hands 



one would expect, but healthy trees, with straight 

 trunks, 20 feet to 30 feet high. 



There is no highly-paid forester for the five 

 square miles of forest on the Hafod Estate, 

 only an ordinary workman, who has grown up 

 with the trees he helped to plant. He certainly 

 knows how to plant successfully and thin judi- 

 ciously, leaving the trees thicker on the windward 

 side. 



The study of climate and the prevailing con- 

 again before becoming the property of the father ditions of soil, which some consider necessary 

 of the present owner, Mr. T. J. Waddingham. qualifications for foresters, are absolutely worth- 







■■ 



plant. 



Green (chlorophyll-bearing) plants manufacture 

 their food, a6 is well known, from the carbonic 

 acid of the air, by means of the small chlorophyll 

 grains in their leaves, and by the action of sun 

 and water. This physiological process is known 

 as " assimilation." 



The first visible product of assimilation ia 



starch. The starch again undergoes certain 



iianges and forms carbohydrates (e.g., BUgara), 



and sugar, which are used as food by the plants. 



In other words, the manufacture of food neces- 

 sary for the growth of the green plants takes 

 place in the chlorophyll-bearing portions. Fungi 

 possess no chlorophyll. Hence they are not able 

 to utilise directly the carbonic acid of the air. 

 They are compelled to search elsewhere for the 

 carbohydrates essential for their development, 

 and accomplish this by living upon substrata 

 from which they are able to obtain a M ready- 

 made M 



They may be con- 





FlG. 94. ROADWAY AT HAFOD; AT THE POSITION MARKED X IS SOIL OVERLYING 



A SHALY DEPOSIT 



Turning sharp to the north by the said gate- less for planters in East Cardiganshire, as the 

 w ay, the road is cut through the tail of the first cannot be altered, and there is no choice 

 mountain. The slope of the rock facing east of the latter. I presume that there are very few 



was covered with Asplenium trichomanes ; but I 

 could only see three specimens on the opposite 

 side. We were now in full view of the hall nest- 

 ling amidst the wildest surroundings. The ap- 

 proach is flanked on each side with healthy plants 



of Abies nobilis, 15 feet to 20 feet high, planted one cubit to the stature of the trees, and as a few 

 <>n breadths of lawn a few yards wide, and that years cannot make much difference to the growth 



supply of food. Parasitic fungi live in 

 various ways upon plants. 



fined to the surface entirely like the mildew 

 fungi, when there will be produced on the 

 mycelium peculiar suckerlike organs — so-called 

 haustoria — by which they absorb their food from 

 underlying cells. Other fungi, by far the 

 greatest number, live within the tissues of the 

 host plant. They may also produce haustoria, 

 but more generally the absorption of food takes 

 place directly by the action of the vegetating 

 hyphae on the infected tissues. 



Following the growth and development of 

 parasitic fungi, a collapse of those cells which 

 have been robbed of their contents takes place, 

 and the earliest symptoms of disease appear. 

 Often the infection is exceedingly local, and the 

 result is the production of smaller or larger spots 

 of dead tissue. The shot-hole fungi of Plums, 

 Cherries, and Peaches illustrate well this pecu- 

 liarly confined growth. 



Other fungi may attack, besides the leaves and 

 fruit, the young shoots of trees, and destroy last 

 year's growth, and thus much of the expected 

 harvest. Others, again, cause cankers which 

 spread from year to year until the whole branch 

 is ringed and shut off from the food supply. 

 Formations like the enlarged portions of 

 plants, which occur in Potato canker, Plum 

 pocket, club root, &c, are also very common. 



It next becomes necessary to consider briefly 

 the question of the predisposition of plants to- 

 wards disease. The word predisposition may not 

 be fortunately chosen to describe the peculiar ob- 

 servations that may be made in the direction of 

 resistance or susceptibility towards disease. In 

 if any — landowners in these days who think medicine, as well as in plant pathology, we often 



meet with typical cases of immunity in animals or 

 plants. For some reason or other, eome individuals 



^^tmmmmm 



of planting trees on land that will grow some 

 useful crop, unless they plant for shelter or orna- 

 ment. Sir W. Schlich's yield tables are equally 

 valueless. No mathematical calculations will add 



» the only artificial embellishment— no flower- 

 beds or borders. Flowers, mainly for cutting 

 are grown by Mr. James, the gardener, in the 

 Kitchen garden, which is situated by the river- 

 side, where there are good crops of fruit. There 

 *'ere Black Currant bushes of Boskoop Giant 

 lour years planted, with shoots the length of mv 

 talking stick, covered with fruit. 



in«r *? af0d is n0t an old estate > as far as Plant- 

 ed I 8 l S concerned - Th ^ work was only 



JoW, ab ° Ut 10 ° *«"» a §°' when Colonel 



CZ?™ *° the P r °P ert y> »fter the death of 



Colon. $ t 1! P T iousl y » ™ * barren waste. 

 Lionel Johnes built himself a residence, formed a 



of a healthy tree, the time to fall is when the tim- 

 ber is wanted. It requires no trained forester to 

 dispose of the timber; this can be done by 

 auction sales, either before or after the trees are 

 felled. I understood that Mr. J. G. Morris, 

 F.S.I., has a fixed price on the Hafod Estate, 

 and the would-be purchaser of timber can take it 

 or leave it. * The Larch in the Hafod forest is 

 considered exceptionally good; except in the 

 case of small orders, the felling is done by the 

 purchaser, who brings his saw mill into the 

 forest, the nearest station for long timber being 



escape a disease altogether, or remain singularly 

 resistant by recovering unhurt from an attack. 

 Hence modern investigators claim that the suc- 

 cessful selecting of resistant varieties would, 

 sooner or later, decide the question of treatment 

 for diseases. This expectation is undoubtedly 

 quite reasonable, but at present we have only 

 just begun to open our eyes to this fact, and the 

 results obtained so far are more of a scientific 

 than a practical value. Disease resistance to 

 " Rust " has been established to a certain 



Wheat. We must also bear in 



degree 



m 



mind that adaption of disease-causing organisms 

 to new conditions will play a very important role, 

 and at present, whilst there is every hope of 

 improving our knowledge in this respect, our re- 

 sults are not established long enough to speak 



16 miles distant. W. P. i?. ? Fron Haul, Holy- the last word in the breeding to disease-resistant 



well. 



varieties. It would, however, be quite erroneous 



