132 Report of the Bilharzia Mission in Egypt, 1915 



The difference in the point of union of the lateral branches of the gut 

 in the two species is common to male and female. It is a very noticeable 

 feature in the growing worms. The posterior portion of the young worm 

 would seem to be a growing tissue, which, by its continued lengthening, 

 changes the relative measurements of the various parts of the gut almost 

 until maturity is attained. 



The attainment of egg-production is more rapid in B. mansoni than in 

 B. hcematohia. In experimental infectious from P. boissyi eggs were found 

 after six to eight weeks, from Bulliiius after nine to twelve weeks, depending 

 on the intensity of infection and on the host. 



The developing worms and coupled adults reared from BulUnus infec- 

 tions are illustrated in figure on p. 129. 



The question of nomenclature remains now to be 

 NoMENCLATUKE. rcconsidcred in the light of the foregoing results. The 

 generic name Bilharzia, proposed first by Cobbold [92], 

 gained almost universal acceptance, especially in medical works and in 

 contributions on the clinical and pathological aspects of infection. I have 

 used the name Bilharzia in the present report, as it is the one by which the 

 disease is commonly diagnosed. Within recent years, however, the name 

 Schistosoma, given by Weinland [H15], in 1858, has been revived under 

 the present operation of the Laws of Nomenclature. It is the more 

 correct, although Cobbold states that under the laws in use at the time, 

 Weinland accepted the priority of Bilharzia over Schistosoma. If the 

 former generic term is used, the species should read, Bilharzia hcBinatohia, 

 and if the latter Schistosoma hcBmatohiiim. It is to be hoped that on 

 grounds of use and suitability, the specific names of Bilharzia hcematohia 

 and Bilharzia mansoni may retain their present application. Doubtless 

 some day, it will, however, be noticed that the Distomum hcsmatobium 

 originally named by Bilharz, was based upon mixed material, and is, there- 

 fore, a composite species. Harley, the first reviser of the species, spHt 

 this -D. h(Bmatohiiun into two components. To the species giving solely 

 terminal-spined eggs, he gave the name D. capense, restricting the name 

 D. hcBmatohiuvi to that form found in Egypt which produced both kinds of 

 eggs. I foresee that the name B. hcematobia may thus be reserved by 

 purists in nomenclature to the single specimen described by Bilharz, which 

 conforms with these requirements. 



There finally remains the Bilharzia magna found by Cobbold in a 

 monkey. The type and only specimen, is preserved in the Hunterian 

 Museum. It is a fragment of a male. I have been quite unable to identify 

 it with either of the species now recognized in man. This is a happy 

 circumstance, for we may now without anxiety retain the specific name of 

 B. mansoni (with which the whole species problem has been indissolubly 

 connected), in its rightful place to recall for future students the insight of 

 one who took no part in controversy, but silently worked through others 

 less inspired, for the eradication of many of the great pests of the Tropics. 



