82 PITTONIA. 
herbage too of whieh the sheep are fond enough. Whether 
this plant be a true grass or some sedge in a sterile condition 
Tam unable to say ; but, at all events, it seems to give promise 
that grass lands lost here by the sands may ultimately renew 
themselves. 
Upon the curious question of the origin of our insular flora 
in general, that of San Miguel in particular gives no new light. 
With its vast preponderance of endemic plants and such 
others as are unknown on the continent the mystery remains 
the same, or is even made more obseure, especially in view of 
the faet that this island is before all the others favorably 
located for receiving accessions from all along a vast north- 
eastward stretch of mainland territory, and from a region the 
climate of which is, in kind, its own. If the insular flora be 
the actual survival of an old flora of the continent, as my friend 
Professor Le Conte suggests, I would remark, without calling 
in question the probable correctness of that theory, it is not a 
little singular that none of these commonest plants of San 
Miguel have survived at any of those points along the coast 
where the climatic conditions are altogether similar, As I 
have indicated in my sketch of the Santa Cruz botany, a few 
insular plants occur in an enfeebled state at a few stations 
along the mainland shores; and these, it will be maintained, 
are the co-survivals, on the continent, of the same primeval 
vegetation still abounding on the islands, a supposition which 
would seem a little more plausible if these specimens were 
found, as they never have been, in any other places than 
where they would inevitably have been landed in case they 
had come from the islands by help of wind and wave. The 
most perplexing of the cases in this particular category is pre- 
sented in the flora of San Miguel. It is that of M. esembrian- 
themum crystallinum, than which no other one species of 
plant is so widely prevalent there, or grows in such rank 
luxuriance. All the hundreds of acres of higher and some- 
what argillaceous land -are thickly covered with it, the single 
specimens not rarely spreading over a six-foot breadth of 
ground. It is this which the unbotanical visitors see so much 
