158 A Bescriftion of the Thread-worm, Filaria immitis. 



life history of hfematozoa is acceptable. With this end in view, in 

 the ' Lancet,' March 8, 1873, I gave a short account of some worms 

 sent to Netley by Dr. Lamprey, A.M.D., with a brief statement 

 that " they were taken from the heart of a dog at Shanghai on May 

 20th, 1865, and found in both ventricles and for some distance 

 along the course of the aorta ; " and to my description of the worms 

 I appended a few remarks on the presence of nematodes in the blood 

 of animals generally, relative to the filaria in the blood of man and 

 the ova and larvas of a nematoid worm in the urine. These worms 

 had been preserved in alcohol since 1865, and were all females 

 containing ova and embryos, yet they were not sufficiently nume- 

 rous or perfect to allow of a complete inquiry into all the anatomical 



Explanation of Plates — continued. 



Fig. 8. a X 300, h x 475 diameters. — Germ cells found in the ovarian tulies 

 and the uterine canal occupying tlie lower third of tiie body of the worm. The 

 degree of maturity of the cells is traced from below upwards in the Plate. Free 

 sperm cells are present, as well as others attached to the germ cells (6). 



Fig. 9 X 300 diameters. — Germ cells — ova, taken from the middle third of 

 the uterine canal. In most the yolk is in a state of segmentation, a few are 

 abortive. Intermingled are free spermatozoa (c). 



Fig. 10 X 300 diameters. — Contents of the uterine canal, towards its termina- 

 tion in the vagina, and in the upper third of the body of the worm. Abortive 

 germ cells ; segmented yolk of irregular shape, surrounded by the egg-wall ; 

 coiled-up embryos, loosely retained within the capsule; free young worms («). 



Fig. 11. — Male worm, natural size; anterior two-thirds of body curled up for 

 convenience of sketching; posterior thii'd, spiral tail end, in the normal condition. 



Fig. 12. a X 300, h x 475 diameters. — Sperm cells common to the entire 

 sperm-producing tube throughout the body length of the worm. 



Plate XXXII. 



Fig. 13 X 25 diameters.— Head end of the male worm, showing its general 

 outline and the following parts : — («) mouth, (/)) ojsophagus at its junction witii 

 alimentary canal, (c) sperm duct coiled on itself, (t/) cuticle, (<;) muscular layer, 

 (/) free granular material within the musculo-cutaneous enveloping tube, " tube 

 charnu." 



Fig. 14 X 25 diameters. — Tail end of tlie male, spirally arranged. The ex- 

 treme end viewed laterally, and showing, within the tip, in the concavity of the 

 coiled body of the worm, the exserted spiculum and the generative appendages. 



Fig. 15 X 25 diameters. — Tail end of the male worm viewed from above, show- 

 ing its vertical compression as compared with the lateral cylindrical contour of 

 Fig. 14, the rows of delicate imbricated epithelium, the arrangement of the 

 internal seminal tubes, and the bases of the geneiative appendages. 



Fig. 16 X 300 diameters. — Latei-al and slightly oblique view of the male 

 generative organs. 



('() cuticle, CO longitudinal muscular layer, (c) oblique muscular layer, 

 ((/) muscular layer for retraction of penis, {e) muscular layer for protrusion and 

 withdrawal of penis, (/) muscular layer for protrusion of penis, ((/) spiculum or 

 penis, (A) sheath of penis, (;) common sperm duct, continuous with {I) vas 

 deferens, and {m) horse-shoe duct of («) generative ap[)endages (vesiculas semi- 

 nales ?), (;>) cascal termination of alimentary canal. 



Fig. 17 X 850 diameters. — Free young female worm, taken from a blood clot 

 in the left ventricle of the heart. 



Fig.' 18 X S50 diameters.— Outlined red and white blood corpuscles taken 

 from the same blood clot for comparison with the young brood. 



