L YCO PODIA CE& 61 



are excessively minute, and have three radiating lines meeting at the 

 apex. Their germination is unknown. 



In most species of Lycopodium vegetative propagation takes place 

 by means of axillary bulbils, which become detached ; and in some, 

 adventitious buds are also produced lower down on the stem. L. cer- 

 nuum produces similar gemmae or bulbils on the root. Phylloglossum 

 is propagated by the lateral budding of its underground tubers, in a 

 manner somewhat similar to our native species of Orchis. 



The species of Lycopodium are scattered over the whole globe from 

 the polar to the equatorial regions, the greater number growing on 

 elevated ground or in swamps ; some are epiphytic. The monotypic 

 Phylloglossum Drummondii (Kze.) is a native of swamps in Australia and 

 New Zealand. Several species of Lycopodium have an ancient use as 

 cathartics. The spores are used in the manufacture of pills, and have 

 the property, from the large quantity of oil which they contain, of keep- 

 ing the hands dry when dipped in water. Those of L. clavatum are 

 collected in large quantities, especially in Northern Germany, for pyro- 

 technic purposes. The British species are popularly known as ' club- 

 moss ' and ' stag's-horn moss.' 



ORDER 2. PSILOTE^:. 



This order is composed of the two very small tropical genera Psilo- 

 tum (Sw.) and Tmesipteris (Bernh.), of the latter of which very little is 

 known, it never having been examined in the living state. 



The stem is erect, and is penetrated, in Psilotum, by a cauline 

 ' vascular' bundle of very simple structure, which is circular on transverse 

 section, and is surrounded by a bundle-sheath. It always branches 

 dichotomously. Psilotum is entirely rootless, the function of roots 

 being performed by remarkable underground branches of the stem, 

 which dichotomise like the aerial shoots. These underground shoots 

 have a three-sided apical cell, and are entirely destitute of a root-cap. 

 Those only which are nearest the surface have a few whitish subulate 

 rudimentary leaves ; these may turn upwards, develop chlorophyll, and 

 become ordinary aerial shoots. Those branches which strike deeper 

 into the soil are slenderer, and the rudiments of leaves are reduced to 

 groups of a few cells which remain buried in the tissue, not projecting 

 above the surface. They resemble true roots in their single axial 

 'vascular' cylinder. Psilotum triquetrum (Sw.) produces minute gemmag 

 or bulbils, which remain dormant for a time, and from which the plant 

 not unfrequently makes its appearance apparently spontaneously in 

 orchid- and palm-houses. The leaves of Tmesipteris are erect, elliptical, 



