[ ^6 ] 



1balf:^an^1bour at tbe fIDicroscope, 



Mitb /Ilbn ITutfen Mest, ff.X.S,, 3f»1R./II>.S., etc. 



Plates L, IL, III., IV. 



Stellate Hairs amongst the Sori of Platycerium alcicorne 



(PI. I., Fig. i) are both beautiful and interesting. The great 

 difference between the lax, sparsely divided, greatly produced, hairs 

 of the frond, and the compact, multifid hairs of the sori, is a sig- 

 nificant fact. 



Anchors, Synapta inherens (PI. I., Fig. 2). — Synapta "is 

 abundant, buried in mud-banks, at and a little above low-water 

 mark, on the shores of Belfast and Strangford Loughs" (Wyville 

 Thomson, Q.M./., 1862, p. 131). A. de Quatrefages' so called 

 S. Duserncea is a synonym ; a closely allied form frequently met 

 with on the English coast. S. digitata has been carefully described 

 by Johannes Miiller (Ueber Synapta digitata, Berlin, 1852). An 

 elaborate memoir on the anchors and calcareous plates of the genus, 

 by the late W. D. Herapath, appeared in the Quarterly Journal of 

 Micro. Science some years back. Wyville Thomson gives, among 

 other structural details, a most interesting account of the formation 

 of these anchors and anchor plates, from the time when they first 

 become to be visible to that of their completion. 



This slide requires as its complement (failing living specimens) 

 a portion of the skin in its dry state, and a section of the same, to 

 show the projection of the anchors from the surface. There is an 

 important note on the use of these anchors in a work called Reiseii 

 im Archipal der Philippinen, by C. Semper, of which a review will 

 be found in the Q.M.J., 1868, p. 163. "The anchors of the 

 Synapta are by no means, as is often supposed, locomotive organs; 

 when they have laid hold of any part, the animal cannot disengage 

 itself without sacrificing them. They are, it is true, moveable in 

 their basilar plate, but there are not any muscles destined to move 

 them, and the will of the animal has no action on their movements. 

 Besides, the body of the Synapta does not cling to the hand ex- 

 cept when one touches it roughly. In reality, the Synaptse crawl 

 on stones and plants without hooking on to them, and in Synapta 

 J5eseliit\\Q anchors are lodged so deeply in the skin, that M. Semper 

 believed in their complete absence until microscopic examination 

 showed him the contrary." 



