1862.] DR. T. S. COBBOLD ON HUMAN ENTOZOA. 3l3 



of sufficient value for specific separation. Like Dujardin, I have not 

 seen the head of T. elliptica, neither am I acquainted with any good 

 figure of the head'''. Goeze's drawings of T. cateniformis only repre- 

 sent a single row of little hooks ; and it is well known that the same 

 processes in T. cucumerina are very liable to fall off, so much so 

 that it has been described as a bookless tapeworm. Van Beneden 

 regards the two presumedly distinct forms as identical, and, although 

 his representations of the cephalic hooks of T. canina correspond 

 very closely with those of the T. cucumerina, both of Dujardin and 

 Leuckart, he speaks of three or four rows of hooks, whilst Dujardin 

 says there are three, and Leuckart simply describes a succession 

 (" mit einer mehrfachen Reihe"), though his excellent figure (fig. 1 1 8, 

 p. 400, of his work) represents four ; he also describes three or four 

 rows as occurring in T. elliptica. It is therefore evident that varia- 

 tions occur in the same form as regards the head ; and it is more 

 than probable that differences of habitat may be sufficient to account 

 for the variations of size and numerical development of the joints, 

 which Leuckart regards as distinguishing marks between the elliptic 

 tapeworm of the cat and the cucumerine cestode of the dog. Be 

 this as it may, one or other of these forms has been noticed in the 

 human subject several times ; but as regards the source of their 

 larvae we are yet in uncertaint3\ When engaged (1856) in rearing 

 Taenia serrata from Cysticercus pisiformis, I thought I had also hit 

 upon the scoleces of T. cucumerina ; but Leuckart has since extended 

 my experiment by feeding rabbits with the proglottides of T. cucu- 

 merina, without producing any measles. Van Beneden has also tried 

 to produce the young of Taenia elliptica in the rat, but without 

 result. Weinland thinks the Cysticercus of T. cucumei-ina will be 

 found in flies, and that dogs obtain the larvae by their interesting 

 habit of snapping at dipterous insects. This is, at least, ingeniousf . 



29. BoTHRYOCEPHALus LATUS, Bremscr. 



B. latus, Bremser, Blainville, Leblond, Rudolphi, Leuckart, 

 Nitzsch, Mehlis, Chiaje, Owen, Creplin, Haselberg, Siebold, Esch- 

 richi, Valentin, Wawruch, Dujardin, R. Leuckart, Kiichenmeister, 

 Leidy, Weinland, &c. &c. 



Dibothrium latum, Diesing. 



? Tcenia lata, Linnaeus, Pallas, Bloch, Goeze, Batsch, Gmelin, 

 Schrank, Carlisle, Jordens, Rudolphi. 



IT. vulgaris, Linnaeus, Werner, Retzius, Gmelin, Jordens. 



T. dentata, Batsch, Gmelin. 



* I have now (Jan. 27, 1863) procured several heads of T. elliptica, and am 

 still unable to pronounce the two forms to be distinct species. — T. S. C. 



t In connexion with these views of Weinland and Leuckart, I may here men- 

 tion that I have recently been feeding a number of cockroaches {Blatta orientalis) 

 with the eggs of Tania cucumerina of the dog, but I have not succeeded in rear- 

 ing any Cysticerci in their bodies. Not discouraged by negative results (which 

 often advance our science as much as positive ones), I shall presently feed them 

 with the eggs of T. elliptica from the cat ; and if I should succeed in thus giving the 

 cockroaches the " measles," I shall have less hesitation in pronouncing Leuckart's 

 opinion, as to the distinctness of these two tapeworm-forms, correct. 



