Larval Stage 0/ Hypoclerma bovis. 71 



transparent; the older subcutaneous larvaj (third stage) are 

 dull white and marked with darker transverse bands; later 

 on they become noticeably thicker and pyriform ; the colour 

 changes to more of a greyish yellow, and subsequently to 

 dark brown ; these larvse have become incapsulated, have 

 perforated the integument, and produce the well-known 

 warbles in the skin. 



In the months referred to one frequently finds that the 

 spinal larvse have crawled out of the fat and are lying in the 

 spaces between the vertebrae; occasionally they are found 

 with one extremity in the intervertebral spaces. 



On the 28th of last February [1896] I also made an inter- 

 esting discovery ; in a yearling beast with a large number of 

 HijpodermaAixxYdd beneath the skin — the subcutis on the back 

 and loins was violently inflamed and suppurating — three 

 spinal larvge were discovered in addition. On examining the 

 very oedematous oesophagus, I found thirteen (Esirt^s-larvse 

 in the connective tissue between the mucosa and the niuscu- 

 laris ; in size, shape, and colour they were similar to the 

 larvae lying in the spinal canal. 



In the same way on two occasions after this I also met 

 with (Esti'us-\ax\^ in the wall of the oesophagus. (Estrus- 

 larva?. have likewise been found in the oesophageal wall by 

 Curtice ; it afterwards appeared that these were the larvfe of 

 liypoderma Ittieatuin, which occurs in the United iStates. 



The interesting statement is also made by Home tiiat 

 in the case of a young bullock he found the whole carcase so 

 full of IJi/podenna-hiYSQ that it had to be withdrawn from 

 consumption. 



Are these spinal and oesophageal larvae really those of 

 Hypoderma hovis in the first stage? 



The great agreement between the youngest subcutaneous 

 and the largest spinal larvaj in the same animal, the appear- 

 ance of larvai under the skin, coupled with the disappearance 

 of the larvse from the s])inal canal, is a strong argument in 

 favour of the view that this is the case. It is remarkable 

 that no single investigator has met with the larvae on the 

 way from the vertebral canal to the subcutis. Home asserts 

 that he has more than once noticed in the flesh dirty green 

 larva-tracks, which led from the spinal canal through between 

 the muscles to beneath the skin. In one instance, where 

 both subcutaneous and spinal larvae were present, a larva was 

 met with between the spinous processes of the vertebral 

 column ; hitherto 1 have not seen definite larva-passages. 

 It is true that when CEstrusAixxYad are present the epidural 

 fat has a dirty yellow colour; sometimes there is found 



