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visible gap. I am sorry to say that, from my point of view, Dr. 
Sambon’s proofs do not answer this description. 
The second difference between Sch. hceniatobimn and Sch. 
mansoni is said to be given in the different anatomical habitat, and 
the specific pathogenic action of the latter form. We will start with 
the well-established clinical fact that terminal-spined ova alone are 
voided from the bladder, whereas, lateral-spined are met with in the 
faeces. The conclusion generally drawn from this observation, and 
also brought forward in the discussion above mentioned by Sir 
Patrick MansON, is that the lesions of the bladder are 
caused by worms producing terminal-spined ova, whilst the 
almost identical lesions of the rectum are caused by worms 
producing lateral-spined ova ; in other words, that the last-named ova 
appearing in the faeces are derived from the rectal 
lesions. In connection with this point. Sir PATRICK MansON 
asked whether anybody had ever seen a lateral-spined egg in the 
urine. Nobody could answer in the affirmative; indeed, I do not 
remember myself to have specially noticed a lateral-spined egg in 
the urine. Thus far, observations agree very well; however, what 
I should like to point out is that even if I, or anyone else, had seen 
a lateral-spined egg in the urine, I would be unable to consider this as 
a fact of fundamental importance. To me it would appear as an 
accidental exception, due to accidental reasons, to the rule that the 
urine contains terminal-spined eggs only. One may examine the 
faeces of a thousand people without finding an apple-maggot, and in 
the faeces of the thousand and first there is one ; the former observa¬ 
tions show that maggots are not a normal appearance in human 
faeces; the latter observation does not at once demonstrate the con¬ 
trary, but only shows that it is an occasional exception, the chief 
interest of which would lie in the question as to the conditions under 
which the exception occurs. As I have said, I would look at it from 
this jxiint of view, should a lateral-spined egg some time be found in 
the urine. 
Passing to the supposed causal connection of the lateral-spined 
ova with the rectal lesions, I must confess that up to a few years past 
I shared the opinion that the former were derived from the latter. I 
must state to-day that this was a mistake; in many cases the 
lateral-spined eggs do not come from the 
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