Page:The Zoologist, 4th series, vol 1 (1897).djvu/377

Rh

attention was drawn during the last week in July to the fact that in the neighbourhood of Birmingham the China Aster was perishing from some form of blight. On pulling a sickly plant from a flower-bed at King's Hill, Wednesbury, Staffordshire, and examining the roots with a pocket lens, I detected a minute worm. This evidently was the cause of the mischief. On submitting specimens of the annelid to microscopic examination I found it to be an Enchytraeid; and so far as I am aware it is new to science, unless it has been examined by some of the florists and described in journals which I am unable to examine. I should recommend all periodicals which deal with the flowergarden to copy this description.

Friend. This destructive pest is 3–4 mm. or about one-eighth of an inch in length, and when seen at work is of a silvery white colour. It has no coloured blood, and may be called a white worm—no uncommon thing in this group of annelids. It lodges under the epidermis of the root and feeds on the juices and tender vegetable substances, thus absorbing the plant nutriment and preventing the roots from performing their natural functions. It is gregarious, for quite a colony will sometimes be found in one plant. The average number of segments is thirty, and on segment XII. a girdle is developed, somewhat papillose, with a pair of pores associated with pear-shaped bodies. The ventral setæ are absent from this segment, their places being occupied by the pores. In the hinder extremity there are four sets of setæ in each segment, each set containing three setæ. The anterior differs from the posterior, inasmuch as the lateral setæ are in couples and not triplets. Thus in segments II.—XI. we have two setæ in each lateral bundle, and three in each ventral bundle. On segment XII. we find two lateral pairs only, then for a few segments more there are two in the lateral and three in the ventral bundles, while the last ten or dozen segments have four triplets each.