78 
THE PRINCIPLES OF BOTANY. 
tion, by means of which the circles of affinity return into 
themselves. 
“We should find other tendencies than that of Birthworts 
to assume the condition of natural orders stationed in a lineal 
arrangement at very distant parts of the line. In truth San- 
dalworts stand, with respect to the Garryal alliance, and 
Loranths to Amentals, in the same position as New Holland 
to New Zealand, or Kamschatka to Russian America upon 
the maps; the whole world seems to divide them, and yet 
they are stationed within a few degrees of each other. 
“ Thus Loranths, which are often unisexual, approach 
Oleasters somewhat nearly, and Sandalworts come close up 
to the limits of Helwingiads,”* 
The three natural orders of Asarals have been distin¬ 
guished as follows : 
1. SANTALACEiE. 
Sandalworts. — Ovary 1 -celled ; ovules definite , with a 
coated nucleus. 
2. LORANTHACEiE. 
Loranths. — Ovary 1 celled ; ovules definite, with a naked 
nucleus. 
3. ARISTOLOCHIACEHk 
Birthworts. — Ovary 3- to 6-celled ; ovules 00. 
Of these we describe the first and the last orders here, 
reserving the Loranths for a separate article. 
1. The Santalacece or Sandalworts contain 18 genera, which 
are again referred to 110 species, those of North America 
and Europe, including our only native species of Thesium 
linophyllum —bastard Toad-flax—presenting us with more or 
less inconspicuous weeds, while those of New Holland, the 
East Indies, and the South Sea Islands are large shrubs or 
small trees. 
The Thesium linophyllum of Smith’s ‘ English Botany,’ 
T. humifusum of De Candolle, is a somewhat rare British 
plant, which is occasionally found on old exposed grassy 
slopes, on Limestones or Chalks, more or less confined to the 
south of England. We have gathered it at Hartley Bottom, 
on the top of Leckhampton Hill, where we once had the 
pleasure of seeing a clever botanist, who had disputed the 
locality, walk over the plant without recognising it, a mistake 
easily accounted for, as at first sight it is so much like the 
* * Vegetable Kingdom/ p. 786. 
