2iS 



HARDWICKE'S SCIENCE^GOSSIP. 



[Nov. 1, 1866. 



STAR-SHAPED HAIRS. 



HAVING been lately engaged with the micro- 

 scope in examining vegetable hairs, I have 

 come across some rather interesting and curious 

 forms, of which the following is a brief summary :— 

 In star-shaped hairs (I call those star-shaped 

 which have no stalk, or a very short one only, and 

 the branches all starting from one common centre), 

 those found on the stem and leaf of the common 



Fig. 230. 



Virginia Stock are interesting : on the stem they 

 are as represented in fig. 230, a ; on the leaf they are 

 of two sorts, mixed, as shown 

 in fig. 230, a b, one being a 

 double of the other. A hair 

 similar to this is also found 

 on the stem and leaves of 

 the Hop (Hurnuhs lupulus), 

 fi°\ 231. This is a very curious hair, and can be 



Fig;. 231. 



Fig. 232. 



plainly seen with the naked eye. In another plant, 



which I have not yet been able to name, but which 

 seems to be a species of Acacia, the hairs on the 

 under side of the leaf are as represented in fig. 232 

 (/ g h). These have six, seven, or eight branches; but 

 on the upper side of the leaf they have only three, 

 four, or five branches (fig. 232, c d e). The calyx of 



Fig-. 233. 



Abutilonvenosum gives us another example of tiie same 

 sort of hair, and they seem to grow direct from the 

 surface of the cuticle without any stalk (fig. 233). 



Fig. 234. 



In the Mealy Guelder Rose {Viburnum Opulns), the 

 branches of the hairs all start from a short stalk, 

 or knot, and vary a good deal in their number 

 (fig. 231). 



m 



Fig. 235. 



The hairs on the leaf of Leirfzio gracilis 

 (fig. 235) are a very well - known example of 

 the same sort ; but are interesting from "the variety 

 displayed in the number of branches, which show 



