728 PROCEEDINGS OF THE SOCIETY. 



the screen, the first to show the ordinary transverse lines, the second 

 taken with a Gifford's F line (green) screen to try and resolve the dots 

 which were only faintly visible, and the third with the use of mono- 

 chromatic blue light obtained with the apparatus in question, which 

 showed the same diatom clearly resolved in dots. Mr. Spitta con- 

 sidered further remarks were unnecessary seeing the hour they had 

 reached, save perhaps that the apparatus was on view in the adjoining 

 room where the Amphipleura would be shown resolved in the manner 

 he had explained. 



_ The President said they were extremely indebted to Mr. Spitta for 

 this demonstration, and intimated that the apparatus which he had de- 

 scribed would be exhibited in the adjoining room at the close of the 

 Meeting. 



Mr. Conrady said that having had the pleasure of seeing the appara- 

 tus, and the result obtained by its means, he should like to congratulate 

 Mr. Spitta on the successful result of the perseverance with which he 

 had followed up the problem of Amphipleura pellucida until he had at 

 last succeeded in resolving it into clear unmistakable dots. 



A hearty vote of thanks to Mr. Spitta was then unanimously passed. 



_ A paper by Dr. P. E. Shaw on ' An Electrical Method of Taking 

 Microscopic Measurements ' was on the Agenda, but in the absence of 

 the author it was not read in extenso. A diagram of the apparatus 

 drawn on the board was briefly explained by Dr. Hebb, and the thanks 

 of the Meeting were voted to Dr. Shaw for his communication. 





On the motion of the President, a vote of thanks was also cordially 

 accorded to Messrs. Watson and Sons for the loan of a large number of 

 Microscopes, by means of which Dr. Scott's preparations were shown in 

 the room. 



The following Instruments, Objects, &c, were exhibited :— 

 Dr. Dukinfield H. Scott : — The following sections of Fossil Plants 

 illustrating his paper. Catamites communis, young stem, transv. sect, 

 showing pith, wood, remains of phloem, and cortex ; Catamites sp., 

 minute twig, transv. sect, showing ring of vascular bundles and cortex ; 

 C. communis, long. sect, of stem showing wood and diaphragms at 

 nodes ; C. communis, tang. sect, of wood, near pith, showing node and 

 base of a branch ; Calamitcs sp., showing leaves of small twigs in 

 transv. sect.; Calamites sp., minute rootlet, transv. sect, showing young 

 stele, double endodermis, and lacunar cortex ; Calamostachys Binneyana, 

 transv. sect, showing axis, peltate scales, sporangia, and spores ; C. Bin- 

 neyana, transv. sect, of cone showing whorl of bracts ; C. Binneyana, 

 long. sect, of cone showing bracts alternating with peltate scales, bear- 

 ing sporangia ; C. Binneyana, long. sect, of cone showing axis, bracts, 

 peltate scales, sporangia, and spores ; Sphenophyllum plurifoliatum, transv. 

 sect, of stem showing primary and secondary wood, phloem, periderm, 

 and remains of cortex ; S. plurifoliatum, long. sect, of stem showing 

 structure of wood and periderm ; S. Dawsoni, long. sect, of cone showing 



