220 



PARASITES OP MAN 



the structure and development of the young worms, I have to 

 observe that the discovery of the viviparous mode of reproduc- 

 tion in Dracunculus is due to Jacobson. Nearly a quarter of a 

 century ago I recognised the fact that the uterine organs of the 

 adult worm almost completely filled up the perivisceral cavity, 

 and that they were crowded with microscopic worms. Referring 



FIG. 43. a, b, Head and tail of the adult guinea-worm (magnified 10 and 18 diameters 

 respectively); c, embryo (magnified 500 diameters). Original. 



to this " find," the late Sir George Ballingall, of Edinburgh, 

 in his well-known work on ' Military Surgery/ recorded the 

 circumstance in the following terms : " The Assistant Con- 

 servator of the Anatomical Museum in our University has 

 detected in the oviduct of an adult specimen from my collection 

 myriads of minute and perfectly-developed (embryonic) Dra- 

 cunculi. They can be very well seen with an half -inch object- 

 glass, but their structure is best exhibited if the magnifying 



