24 
IOWA ACADEMY OF SCIENCE 
But these time-honored forms might, so far as can he seen, persist 
yet for centuries in their peculiar locations and environments, chal- 
lenging the admiration and wondering inquiry of every intelligent 
man. As already suggested in this paper, such are the delicate adjust- 
ments of nature that even such limited types may indefinitely hold their 
own. In such cases, unfortunately, the activity of civilized humanity is 
a factor for which Nature has made no provisions. The mollusc-eating 
native was here a part of the forest and contributed, as we have seen, 
to the balance of Nature’s equilibrium; but the beef-eating importation 
is too intense. He thrusts his starving herds among these aged trees and 
their treading and crowding are likely to bring speedy extinction to 
these wondrous plants, of lineage remote, the last survivors of America’s 
most ancient forest types. 
The greatest natural enemy of the shore-cypress seems to be the lichen, 
particularly the filmy strands of Rcimalina sp. These flourish under the 
same moisture-laden breezes which seem to vivify the cypress. But 
here again there were compensations. Young cypress trees are less 
afflicted, and the life of the species is accordingly not specially endan- 
gered. Species of Lecanora and Buellia plague the lesser xerophytic 
species, but as the moralist might say: the torment is perhaps not 
greater than may avail for discipline ! 
Concerning the two pines named at the outset of this brief story there 
is less to be said. The Monterey pine is also very limited in its natural 
distribution, though now planted in distant parts of the world. Finns 
muricata has a wider range scattered up and down this coast. It has 
cones in shape and habit not unlike those of P. radiata, but they are per- 
sistently prickly. The cone looks like a cross between P. radiata and P. 
murryana. All these pines have the curious habit .of holding their 
cones, holding them attached to stem and branches for years. Speci- 
mens of the Monterey pine a foot thick may be seen with cones, perhaps 
the earliest set, still, necklace-like, encircling the trunk a few feet from 
the ground. 
Cupressus goveniana has the same habit. P. muricata occupies the 
higher part of the peninsula, from 500 to 800 ft. ; it comes into imme- 
diate, but not threatening competition with C. goveniana; is in fact a 
scrub-pine in that locality and is early fruiting. P. radiata succeeds both 
species on the lower slopes. One passes out of a pure stand of the 
prickly-cone type to an equally pure stand of the Monterey pine almost 
at a step. Probably some slight change in the constitution of the soil 
determines the prevalence of one species or the other at their line of 
