422 Duhlin Microscopical. Cliib. 



December IG, 1880. 



Cross Section of Leech. — Prof, Mackintosh exhibited a cross sec- 

 tion of the body of the medicinal leech, aud called attenliou to 

 the system of anastomosing tubes of different sizes to be seen in 

 the cells of the nephridium. These were very weU described by 

 Bourne, in the July number of the ' Quarterly Journal of Micro- 

 scopical Science ' for the current year. Prof. Mackintosh's results, 

 which were obtained independently, agree in the main with Bourne's. 

 He was not (juite sure, however, that the latter was correct in his 

 supposition (offered with reserve) that there Avas no communica- 

 tion between the duct of the nephridium and the tubules ; but on 

 this point he would not speak with certainty until he had studied 

 the rest of his sections. 



Oljndlum GriffitJisuv, n. s., Perceval Wright. — Prof. E. Perceval 

 "Wright exhibited a number of mountings showing the various 

 stages in the life-history of a new species of Olpidhnn to be 

 called Oljridiirm Griffithsia>, found by him in the as yet unopened 

 fructification of Gri-ffifhsm setacea. Led astray by a])pearances, 

 even though on his guard at the time, Dr. AVright had once, some 

 time ago, showed these as antheridia ; but the antheridia of 

 Grijjithsia have been shown by Thuret to be of the ordinary type ; 

 and an iuvcstigation of these growths for a few days this September, 

 at Dinard, revealed their true nature, the first hint of which had 

 been given to him by Dr. Eornet. Specimens were met with 

 of a fine green, as well as of a pink, colour ; and full details were 

 promised. 



Hitman Spincd Cord. — Mr. P. S, Abraham showed a section of 

 human spinal cord taken from the cervical region, near to the 

 medulla oblongata. The point of interest in the specimen was 

 that in two instances the processes of the large ceUs of the 

 anterior cornua of the grey matter seemed to anastomose with pro- 

 cesses fi'om other cells, an arrangement not generally figured in 

 histological works. — Mr. E. G. Hull likewise showed sections of 

 spinal cord. 



Scctioiis of the Killiney Granite, showing minute Crystals of Apatite, 

 shoivn hi) Prof. Hull. — These appear as long, slender, colourless 

 prisms traversing the quartz of the granite, and in cross section 

 aitparcntly show a polygonal fonn ; but being exceedingly minute, 

 it was dilficult to determine whether or not they were hexagonal. 

 They were visible with a one-fourth objective and No. 1 eye- 

 piece, but with a one-fifth objective were very well defined. Prof. 

 Hartley, F.C.S., had previously tested the specimens from which 

 the slides were made for phosphate of lime, and found it present in 

 very minute quantities in the silica, corresponding to the smallness 

 of the prisms shown in the slides. — Dr. Erazer stated that he had 

 obtained a crystal of apatite from the granite d*" Killiney, but that 

 their occurrence is very rare. 



