( 123 ) 

 PEOGEESS OF MICEOSCOPICAL SCIENCE. 



Bilharzia hcemafobia [Cobhold) in a Manchester Patient. — Dr. Henry 

 Simpson gave the Manchester Philosophical Society an account last 

 year of a case of his in which this rare worm had appeared. Through 

 inflammatory changes leading to loss of substance, the ova become free 

 in the bladder, and are washed away in the urinary secretion in im- 

 mense numbers, along with blood disks and pus-corpuscles. They are 

 generally ovate in form, but vary somewhat in outline. At one end 

 the shell is produced into a short spike, something like that on Von 

 Moltke's helmet. Occasionally this is placed laterally. They vary 

 in length from yi^th to o^xi yth of an inch, and in breadth from 4^0 th 

 to 5-^oth of an inch. The shell is without any distinct operculum. 

 The contents of the egg are seen in all stages of development, from 

 scarcely distinguishable granules, enclosed in a vitelline membrane, to 

 the perfectly-formed ciliated embryo, exhibiting active movements of 

 the body and raj)id play of the cilia while still enclosed in the shell. 

 Sometimes the head of the embryo lies towards the spiked end, some- 

 times to the plain end of the shell. Free, living embryos are often 

 met with in the urine, and it is curious to watch the mode in which 

 they escape from the shell. The general shape of the embryo is ellip- 

 tical ; they are abundantly sujjplied with cilia, especially at the ante- 

 rior extremity, and show distinct traces of a water vascular system. 

 The develoi^ment of this entozoon in all probability follows the same 

 general plan as that of the other Trematode worms, or Flukes, which 

 pass through several phases or alternations of generation ; one or two 

 intermediate hosts, generally mollusca or aquatic larvae, being neces- 

 sary before the adult fluke becomes parasitic in the body of the verte- 

 brate animal destined to be its host. 



Mode in ivhich Cliona burrows. — Mr. Edward Parfitt publishes a 

 paper on this subject, and the boring of mollusks. He differs from 

 Dr. Hancock, who says, in regard to Cliona, " that no other excava- 

 tion, whether of worm or mollusk, presents a surface anything like 

 that of the burrows of sponges ; and were no other proof at hand, this 

 puncturing would be sufficient to establish the fact that they possess 

 the power of enlarging their habitations." Now, says the author, if 

 Mr. Hancock's assertion be right, these silicious tools ought to leave 

 their marks on the walls of the holes accordingly. We should have 

 either lines corresponding with the direction of the burrows or trans- 

 versely, or both, according to the contracting of the investing membrane ; 

 but so far as he has investigated this subject, he has not been able to 

 detect any scratches of this kind. In fresh-bored cavities into solid 

 shell, the walls are lined with the thin, pale, yellowish process of the 

 sponge, composed of the investing membrane and the inner sarcode, 

 on which was scattered a few sponge cells. In these membranes are 

 stuck, almost at random, a few spicules, the principal use of which is 

 to hang on the investing membrane, and it is on these that the sarcode 



