Marcu 18, 1897 | 
NATURE 
463 
accidentally introduced into Europe. Déasfz's amygdalz, a very 
destructive coccid, was described by Tryon in 1889 from 
Australia ; already we knew it aiso from various localitiés in 
the Oriental, Palzarctic, Ethiopian, Nearctic and Neotropical 
regions! Very many other such cases might be cited, showing 
that there is great need for speedy investigation, before the data 
regarding the true habitats of these and other organisms become 
impossible of discovery, owing to the extermination of some 
Species, and the dissemination of others. 
T. D. A. COCKERELL. 
Mesilla, New Mexico, U.S.A., February 12. 
Formation of Coral Reefs, 
I HAVE read with much interest the description in NATURE of 
the attempt of Prof. Sollas to bore through the rim of the 
Funafuti Atoll. 
I should like to know what ground he has for believing that 
the soundings obtained by the officers of the ship which conveyed 
him to the island, support Darwin’s theory of the formation of 
-coral atolls ; for there does not appear to be any new feature in 
the section printed with his letter. It is similar to many other 
sections of atolls in the China Sea and elsewhere, which have 
been published from time to time by the Hydrographic 
Department. 
As this attempt has failed, it might be well to turn attention 
to a more accessible part of the Western Pacific. 
The Fiji islands are a complete museum of corals, and contain 
reefs of every sort of formation. Many of these appear to 
support Darwin's theory. The Lau, or eastern group, has been 
elevated, and contains some ancient coral reefs many hundred 
feet above the sea, The island of Naiau is 580 feet high, and 
has a rim summit of coral enclosing a depression which, if my 
recollection serves me, is about 200 feet below the top. If 
Darwin’s theory is correct, this ancient atoll must have been first 
formed by subsidence, and subsequently elevated to its present 
position. Borings would probably reveal the lost peak not far 
below the floor of the central depression. 
The island of Kambara, 470 feet in height,-is of similar 
formation. 
A close geological examination of Naiau or Kambara would, 
in all probability, end the controversy, for the borings into the 
base of the island, commencing some. hundreds of feet above the 
sea, but below what I suppose to be an ancient atoll, could be 
easily undertaken, and ought to prove at once the nature of the 
foundation upon which the reef rests. 
With regard to the concluding paragraph of Prof. Sollas’ letter, 
he has apparently overlooked the fact that a live specimen of 
reef-building coral (Astrzea) has been dredged up from a depth 
of forty-five fathoms 2 ¢he /agoon of the Tizard bank by Dr. 
Bassett-Smith, of H.M.S. Rambler. This specimen is in the 
Natural History Museum. W. UsBoRNE Moore. 
8 Western Parade, Southsea, February 25. 
Chinese Yeast. 
A FRIEND has sent me a few ounces of what he calls Chinese 
yeast, a white substance which, so I understand, possesses the 
power of converting rice grains into a soluble substance, which is 
then allowed to ferment until it is converted into alcohol. 
Perhaps some of your readers could refer me to a more detailed 
account of the properties of this yeast. I shall be pleased to 
send samples for cultivation to anybody who would care to 
undertake it. C. E, SvROMEYER. 
6 Jedburgh Gardens, Glasgow, March 6. 
DINOSAURS} 
ics is only sixty years ago since George Catlin wrote 
his “ North American Indians,” and graphically de- 
scribed the vast herds of bison, numbering millions of 
individuals, travelling for days together across the rolling 
prairies ; yet we have seen these disappear, like the 
aborigines, and their places usurped by the “cow-boy,” 
and by countless herds of domestic cattle. 
1 “The Dinosaurs of North America.” By Othniel Charles Marsh. Wx- 
tract from the Sixteenth Annual Report of the United States Geological 
Survey, 1894-95. C. D. Walcott, Director. Imperial8vo. Pp.133 + 414. 
Pl. ii + Ixxxv. (Washington, 1896.) 
NO. 1429, VOL. 55 | 
| 
If we could only wind the clock of Time still further 
backwards, and make him disclose, with moving-photo- 
graphic-vividness, some of those earlier Mesozoic scenes 
on the American continent, or even in our own little 
island, for that matter, we should find, not herds of bison, 
but far other cattle, though some wore horns, and were 
big and ugly enough in all conscience; yet they were 
mostly harmless, and herbivorous in diet, but belonging 
to patterns now entirely obsolete, like the old ‘ brown- 
bess” of our grandfathers’ days, only more so. 
And, doubtless, it is due to the extreme rarity of pre- 
servation of old land-surfaces, as compared with the far 
more numerous and abundant records of marine areas 
which have come down to us, that renders their discovery 
of such paramount interest to the biologist and geologist. 
The vast physical changes also which they indicate are, 
undoubtedly, owing to the immense and unmeasured 
periods which have intervened, filled only by the slow- 
music of the sea. 
Thus, after parting company with Eocene Mammals, 
such as 7?oceras, we take a plunge in the sea of time, and 
come again on shore to find that all but the tiniest of 
Mammals are absent, and the land is peopled by huge 
herbivorous and somewhat lesser carnivorous Dinosaurs 
in their stead. 
Although this strange reptilian order was discovered 
so early in this century, it 1s only within the last thirty 
years that, thanks to Prof. Huxley, we have been led to 
understand them ; and not till 1881, had we a correct 
notion even of the skeleton of our own famous /gwazodon, 
though Mantell had commenced to record the discovery 
of its bones in Sussex in 1825. 
One of the most curious points about these medieval 
animals is, that they make their earliest appearance in 
the Triassic period, and were first known in North 
America some sixty years ago, not by their bones or 
teeth, but by their footprints. These tracks, discovered 
so abundantly on the fine-grained, often fissile, sand- 
stones of the Connecticut valley area, were at first 
attributed to birds, although any birds earlier than the 
Tertiary period were then unknown. 
Yet the genius of Huxley had demonstrated (in 1858) 
that in the Dinosauria we are dealing with a group ot 
reptiles which most nearly approached the flightless 
birds, not merely in the weakness and smallness of their 
fore-limbs, but in the structure of the pelvis, the ilam 
prolonged forward in front of the acetabulum as well as 
behind it, and the long rod-like ischium and pubis being 
all strongly ornithic characters ; the head of the femur 
being set-on at right angles to the shaft of the bone, so that 
the axis must have been parallel with the median vertical 
plane of the body, as in birds. The metatarsals were free 
as in young birds, not anchylosed together as in adult ones ; 
moreover, in Zgwanodon and some other forms met with, 
the number of functional digits was three, as seen in the 
foot of Dinornis, and in the great majority of living 
birds, and the number of the phalanges agrees with that 
in the II, III] and IV toes of the Emeu and Rhea, 
or any other typical bird’s foot. So that there is good 
reason to conclude that the Connecticut footprints, instead 
of being those of birds, were certainly the tracks left 
behind by the écvd-like Dinosaurs of that period. 
From the great difference in size between the fore and 
hind limbs, Mantell and Leidy concluded that the Zgw- 
anodon, and some others of its kind, may have supported 
themselves for a longer or shorter period upon their 
hind-legs. ‘This conclusion was further confirmed by the 
discovery made by Mr. S. H. Beckles, F.R.S., of huge 
three-toed footprints occurring in pairs upon ripple- 
marked surfaces of Wealden sandstone near Hastings, 
of sucha size, and at such a distance apart, as to lead 
to the conclusion that they were undoubtedly made by 
Jeuanodon. Mr. Beckles’ discovery has since been con- 
firmed by the observations of Louis Dollo upon the 
