144 WORMS. 



may do no great harm during their residence in the 

 stomach of the horse. The advice, therefore, to the 

 owner would be — let them alone; or, at most, be 

 content with having them picked off when they appear 

 beneath the tail. There are two good reasons for 

 this ; —the first is, that there is not any medicine that 

 will expel them : the strongest and even the most 

 dangerous purgative is for this purpose insufficient. 

 The horse may be injured or destroyed by the violent 

 measures adopted ; but the bot sets all physic at defi- 

 ance. The second reason is : that, if the bots are let 

 alone, they will, in due time, all come away without 

 our meddling. At the latter end of the spring, the 

 larva detaches itself from the stomach; is carried 

 along the intestines ; drops on the ground ; burrows into 

 it ; and becomes a chrysalis or grub. In a few weeks 

 it undergoes another and more wonderful transforma- 

 tion ; — it awakens from a state of sleep ; bursts through 

 its horny shell; and assumes the form of a fly, to lay 

 eggs and give rise to bots in some other animal. 



There are, however, Worms in the intestines which 

 are more often inj urious to the horse ; yet seldom to 

 the extent which is feared. The small intestines 

 contain a round white worm, from six to fourteen inches 

 in length. This worm (the Lumbricus teres) in its 

 general figure very much resembles the common 

 earthworm ; and it lives either upon the mucus of the 

 bowels, or the nutritive part of the food. A dose of 

 physic will often expel an almost incredible number. 

 The appearance of one or two will at once suggest 

 the propriety of adopting measures for the removal of 

 that which is then known to exist. 



