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THE YUCCA. 



259 



one of the insects very highly magnified, as seen when crawling along ; and fig. c represents 

 a very young animal when lying on its side in a state of inactivity. 



The bristles terminating the body, together with tho structure of the legs, rather than the 

 structure of the body itself or the head, indicate the tribe to which the insects belong, namely, 

 the AcaridEB, or mites, where they range apparently in tho neighbourhood of the genus 

 Tetranchus, which includes the web-spinning species of the Lime, and also the "red spider" 

 of the greenhouse. 



Professor Westwood had received 

 from Blantyre, as late as- the beginning 

 of July, specimens of infested buds, 

 with the insects still in their spring four- 

 footed condition. The disease, which was 

 quite general in that district, had been, 

 it was stated, known for 20 years, and 

 after a plant becomes infected very littla 

 fruit is to be obtained from it. The 

 young animals have also been observed 

 hatching from their eggs during the 

 winter. It is evident that they retain 

 their four-legged juvenile form for a 

 considerable period, but later they 

 [acquire six legs, as was seen in speci- 

 mens from old buds gathered near the 

 end of October, when some of them 

 had two well-developed bristles at the 

 tail. The young larvae were at the 

 same time to be found in the buds 

 forming for the next year's crop. 



Messrs. Duges and Turpin many 

 years ago published the description 

 and figure of an allied minute insect 

 which they had detected in the galls 

 of the Lime and Willow trees. These 

 had an elongated body, small sucker, 

 with two short thick lateral palpi, and 

 two pairs of 7-jointed legs. These minute animals Duges considered to be larvse, from the 

 paucity of legs, and he noticed their close resemblance to the Tetranchi found occasionally in 

 similar galls. 



The chief remedy in the case of badly infested trees is to prune them very 

 closely in autumn, but this may advantageously be supplemented by picking off 

 the old dried buds in August or September, as it is evident that otherwise the 

 newly formed buds must become infested almost as soon as they are well de- 

 veloped in the early part of the autumn. A dressing of the shoots at that period 

 with a thick coating of lime and soapsuds, to prevent the females from crawling 

 to the young buds, has been also suggested. M. 



THE YUCCA. 



j S a decorative plant for the lawn, the shrubbery, or the recesses of bold 

 rockwork, the Yucca stands unrivalled. No other plant possesses so dis- 

 tinctive a character, while the exotic appearance of the Yuccas especially 

 recommends them ha these days, when diversity of foliage is so much 

 sought after. They are, indeed, hardly ever out of place, and suit any position 

 or situation, whether used as single plants, or as groups, on the lawn, or in the 

 shrubbery borders, in beds, or planted either at the base, the sides, or the summit 



