WITH REFERENCE TO THE POTATO DISEASE. 65 



tubers to vegetate, it will be found necessary to lay the haulms 

 of the plant down in a slanting or oblique direction, so as to let 

 the exposed tops of the haulm reach only to the centre of the 

 valley or furrow, thereby gaining the double advantage of room 

 and protection." 



In the absence of the diagrams which accompany the pamphlet 

 the mode of inclining the tops will be sufficiently understood bj^ 

 supposing the rows to run north and south ; then the haulm will 

 be laid, not pointing to the west, but to the south-west. 



No. 18, a variety of potato from Norway, planted in the same 

 quarter, afforded more sound produce tlian the other variety 

 treated in the usual way. 



Results Nos. 20 to 33 are from a number of seedlings, the 

 produce of which proved all badly diseased, affording additional 

 proof that seedlings are as liable to be attacked as old varieties. 

 No. 30 was raised from a variety received two years ago from the 

 north of Finland, the tubers being sound after enduring tlie sea- 

 voyage, packed in the hold of tlie ship. 



Nos. 37 to 54 were from drier soil in tlie Experimental Garden. 

 The tubers were planted whole in hills, as suggested by the 

 raisers of the varieties, Messrs. Hardy and Sons. It appears that 

 planting in hills was disadvantageous in this instance ; as was 

 also the case in 1847 (see Vol. III. p. 55). The average sound 

 produce of Nos. 37 to 45 was 4 tons 10 cwt. 66 lbs. per acre. 

 The same sort planted in rows, Nos. 55 to 58, averaged 5 tons 

 13 lbs. In hills the diseased portion averaged 5 tons 1 cwt. 

 3 lbs. per acre ; in rows only 1 ton 17 cwt. 56 lbs. 



Nos. 55 to 65 exhibit the results of the method proposed by 

 Dr. J. F. Klotzsch to protect potatoes against disease. It con- 

 sists essentially in this : " During the fifth, sixth, or seventh 

 week after the tubers have been planted, or in the fourth or fifth 

 week after the planting of rooted shoots, or at any time when the 

 young plants have reached a height of six or nine inches above 

 the ground, the tops of the branches are lojiped or clipped 

 [pinched off] by means of the thumb and first finger, to the 

 extent of half an inch. This operation must be repeated the 

 tenth or twelfth week after planting, it being immaterial at what 

 hour of the day." The ground for experimental purposes in the 

 Society's garden being limited, tlie sets for this experiment could 

 not be planted so early as would have been desirable. They 

 were planted the first week in May. When between six and 

 nine inches above ground the plants were treated according to 

 the above recommendation. But by the time that ihe opera- 

 tion ought to have been repeated, it had been severely performed 

 by the disease. The results, however, give on the average a 

 slight balance in favour of stopping. The method seems to 



VOL. IV. F 



