124 PROCEEDINGS'JOF SOCIETIES. 



Dr. M'Donnell observed that the life history of this worm had 

 been well worked out bj' German investigators. Existing, suppose, 

 in the muscle of a mouse in what is known the encapsuled state, it 

 remains, and seemingly would always remain, in the larval condition. 

 If this mouse, however, is eaten by a cat, the encapsuled larval 

 Trichinse get into the intestinal canal, and there grow, and their 

 sexual development becomes complete. They have offspring, which, 

 while still very small, penetrate the wall of the intestine, migrate 

 through the body, and finally take up their abode in the voluntary 

 muscle of the cat, there to remain until it, in its turn, falls a prey 

 to some flesh-eating animal. Dr. M'Donnell exhibited several pre- 

 parations showing the minute worm coiled up within its capsule in 

 the muscle, and also taken out of the capsule by dissection. 



Mr. Archer once more ventured to show Conocliihis volvox, in fine 

 condition ; but this would not be worthy of another record, except 

 to mention that the numerous specimens to be seen were taken from 

 under ice some three or four inches in thickness (during the late 

 brief and sudden frost), which had to be smashed with a heavy 

 stone, after some labour, before a gathering could be made. More- 

 over, the specimens had been nearly three weeks in the house, 

 whilst sometimes in warmer months they had disappeared ere as 

 many days. As it is sometimes thought that fine objects of inte- 

 rest are not to be had in winter, this reference to this striking rota- 

 torian may not be thought wholly uninteresting. 



Dr. Alex. Dickson exhibited the " Protonema " of Schistostega 

 osmundacea, showing the curious structure presented by the confer- 

 void filaments giving ofi" here and there a globose cell, which, in its 

 turn, gave ofi^ by constriction strings and clusters of similar cells, 

 each eventually cut ofi" from its neighbour by a septum, thus 

 originating an almost fruit-like structure. To the presence of these 

 globose cells, which contain chlorophyll, is due the peculiar green 

 lustre presented by this moss. 



Dr. Moore had taken this pretty little moss in Yorkshire, and 

 had it under successful cultivation. 



Dr. Dickson further showed the unicellular hair-like roots from 

 the thallus of Marchantia. These were seen to present the remarkable 

 character amongst vegetable cells of possessing a secondary internal 

 deposit, in the form of minute spine-like processes extending 

 into the cell-cavity. It sometimes seemed as if these ran in 

 a spiral direction, and occasionally the whole filament assumed a kind 

 of spiral twisting, to use a familiar illustration, comparable to that of 

 a stick of barley sugar. Dr. Hofmeister mentions a somewhat 

 similar form of deposit in the hairs of the related genus Riccia, as 

 well as Marchantia, to which Dr. Dickson referred. 



Birmingham and Midland Institute. 



The Second Annual Dress Conversazione of this institution was 

 held in the Town Hall, Birmingham, on Wednesday evening, 

 December 4th, 1867. The invitations to this meeting are 



