ROUGH EQUISETUM. 
23 
The catkin is small, dark coloured, apiculate and terminal, or 
rarely lateral, and then very near the apex ; its scales are from 
forty to fifty in number, and each is impressed with two or three 
vertical striae. Before the scales have separated in their approach 
to maturity, these striae are continuous throughout the catkin, 
even entering its terminal apiculus, which, in consequence, as- 
sumes a polyhedral figure : they generally correspond in number 
with the striae of the last internode, thus leading to the suppo- 
sition that the catkin is a metamorphosed portion of the stem. 
Mr. Brichan^' has noticed the occasional presence of a singular 
pile of cones on the stems of this species ; I will describe it in 
his own words. — On the top of many stems of E. hyemale I 
observed a pile of small, dark brown, membranous, elastic, co- 
nical, inverted sheaths, of the same substance as the teeth of the 
sheath which embraces the catkin, increasing in width upwards, 
and so closely embracing each other that the rim only of each 
is seen, except the highest and largest, which gives the top of 
the pile a conical shape. Although scarcely an inch in length, 
it resembles an inverted abortion of the plant. Its lower end 
is at first inserted in the uppermost sheath, and surrounded by 
several small sheaths of a texture similar to its own, and placed 
within each other. It is afterwards quite protruded, and gra- 
dually falls off, leaving a flexuous apex, somewhat like that of 
the catkin, whose formation I am persuaded it precedes. On 
dissecting the top of several stems from which the pile of cones 
seemed but recently to have fallen, I found the germ of the cat- 
kin completely enclosed within its sheath, the teeth of which, 
not yet separate, form by their union the apex which appears 
when the pile falls off. Dissection, however, when the cones 
are present, seems often to discover an abortive germ. The 
number of inverted sheaths in one of these piles is about twelve ; 
what their peculiar function may be I cannot even conjecture.” 
The spores or supposed seeds of Equisetums have long been 
favorite objects with the microscopist. The figures given below 
represent the spores of the present species in various stages of 
development : they are copied from the illustrations to a paper 
* Pliytologist, -374. 
