May 28, 1885] 
NATURE 
ks 
_ The polyps bear the gonads, and are apparently vivi- 
parous. Very interesting conclusions are arrived at by 
the authors by comparison of the various stages at their 
disposal as to the mode of growth and successive addi- 
tions of fresh polyps to the colony around the termina] 
primary polyp, and these are at variance with those of 
Lindahl. A couple of lateral polyps appear on each side 
of the terminal polyp, then another pair of laterals are 
formed, and the rachis expands in breadth. The centro- 
dorsal polyp is formed, and then the dorso-lateral are deve- 
loped, whilst the lateral polyps become more numerous. 
H. N. MOSELEY 
OUR BOOK SHELF 
A Flora of the English Lake District. By J. G. Baker, 
F.R.S., F.L.S. (London: George Bell and Sons, York 
Street, Covent Garden, 1885.) 
IT is perhaps surprising that a “Flora” of the Lake 
district has not before been issued, considering the large 
number of botanists who have yearly rambled over its 
fells and dales. It has been left to Mr. J. G. Baker to do 
so, and with modesty he says “‘it does not seem likely at 
present to stand in the way of anything more complete.” 
The limits of the “ Flora” embrace parts of Cumberland, 
Westmoreland, and the whole of what is botanically 
called Lake Lancashire ; but excludes “the northern half 
of Cumberland and the western slope of the Pennine 
Chain, through Cumberland and Westmoreland ;” the 
exact boundaries are, however, not very clearly defined 
One cannot help feeling, directly the book is opened, 
that it is the work of one used to generalise and deal with 
facts in a broad way: inno part more so than in the first 
fourteen pages, where, accepting Mr. H. C. Watson’s 
definitions, he describes the distributive types, zones of 
altitude, temperature, &c., with a clearness coming of 
long and practical acquaintance with the subject, giving 
comparative tables of the types, &c., with those of 
Northern Yorkshire, Northumberland and Durham, and 
Britain, and making the Lake Flora about goo species. 
It should, however, be remembered that this number is 
based on Mr. H. C. Watson’s estimate of 1425 species for 
Britain as a whole. 
Had that estimate to be made wow by Mr. Watson, 
the result would probably be the accepting of a larger 
number, not alone by the discovery of species since 
made, but by a decided feeling on his part “that there 
were some species that would eventually have to be 
divided.” It may well be asked why is there this com- 
paratively large amount of difference demanded among 
our native plants to constitute a “ species,” and the little 
often accepted among newly-discovered “species” from 
distant countries ; doubtless knowledge is progressive in 
the latter case, but still theories and generalisations are 
built up on them with as much apparent certainty as 
on floras long known and: studied. Mr. Baker then 
enumerates the species constituting the flora, running up to 
234 pages, numbering them according to the sixth edition 
“the “London Catalogue,” showing also (but not num- 
ering) the large number of doubtful plants that have at 
various times been reported from the district. 
Perhaps the most striking fact brought out by this 
“Flora” is the scarcity of aquatic species compared with 
the numerous lakes and tarns, of which there must be 
between sixty and seventy, large and small. Whether in 
this particular district this is from the want of investigation, 
or from a real paucity of species or specimens, is difficult to 
‘say ; but certainly our lakes and waters have not been suffi- 
ciently systematically searched, whether from the botani- 
cal, zoological, or chemical point of view. In this we should 
do well to emulate the Swedish naturalists; but in 027 
| 
case it may well be asked, “ Where are we to look for 
help?” 
How little we know of the life-histories of our aquatic 
plants ! and it may well be suggested as a study for those 
botanists, who, while not being able to take up botany in 
the way so ably advocated lately by Prof. Bower in 
NATURE, still have some leisure from other occupations 
and duties, and could really advance the knowledge of our 
flora beyond mere collecting. It is only necessary to turn 
over the plates of Dr. T. Irmisch’s work on them to under- 
stand what is meant and required. AR. B. 
The Fallacy of the Present Theory of Sound. Wy Henry 
A. Mott, jun., Ph.D., E.M., &c., Professor of Chemistry 
and Physics in the New York Medical College and 
Hospital for Women; Author of “The Chemist’s 
Manual,” “Was Man Created?” “ Adulteration of 
Milk,” “Testing the Value of Rifles by Firing under 
Water,” “ The Laws of Nature,” “ The Air We Breathe 
and Ventilations,” &c. 12mo. (New York: Printed 
for the Author, 1885.) 
THIS is a very curious book. Its author appends to his 
name recognised scientific titles, and seems to hold a 
responsible position as a teacher; but he has been led 
into a hopeless and inextricable muddle about wave- 
motion ; and, starting with a misconception, he naturally 
obtains results so utterly at variance with common sense 
and experience, that it is remarkable he cannot see his 
error. 
He begins by admitting that “to attack a theory which 
has been upheld for 2500 years, and which has been and 
is sustained by the greatest living scientists, is certainly 
a very bold undertaking.” But he feels bound, neverthe- 
less, “to come to the front and join Dr. A. Wilford Hall 
in exposing the fallacy.” He fulminates, moreover, the 
following withering defiance at false prophets: “If Profs. 
Helmholtz, Tyndall, Lord Rayleigh, Sir William Thom- 
son in Europe, and Profs. Rood and Mayer in this 
country, wish to retain the respect and confidence of 
thinking people, they will at once endeavour either to 
defend the theory of sound, or, like men, come boldly to 
the front and acknowledge that it is fallacious.” 
There can be no doubt that these various noblemen 
and gentlemen will at once proceed to adopt humbly the 
latter and safer alternative ; because it is obvious that if 
they do not do so speedily, creation and nature will come 
to a premature end. This rather serious occurrence is 
thus predicted : “ The lowest tone of an organ is stated by 
Prof. Blaserna to have sixteen vibrations to the second, 
and a consequent wave-length of 7ofeet. It thus follows, 
says Dr. Hall, that in the sound of such an organ-pipe the 
air-particles (as a whole) are obliged to travel 35 feet and 
back sixteen times each second in order to pass from the 
space occupied by the centre of rarefaction to the centre 
of condensation and back. They would thus move with 
a velocity in one direction of 560 feet a second, or at the 
rate of 381 miles an hour, which would produce a tornado 
of more than double the velocity necessary to sweep a 
village into ruins. If there was the least truth in the 
wave-theory, the sound of a church-organ should get up 
a cyclone which would blow a cathedral into atoms.” 
This is truly very horrible! far worse than dynamite. 
Saddened by these reflections, we can bear with com- 
parative equanimity the revelation that “the prong of a 
tuning-fork moves at the rate of only about one inch in 
four years,” and “instead of swiftly advancing, as Tyndall 
says, sounds audibly when moving more than 25,000 times 
slower than the hour hand of a family clock, and more 
than 309,000,000 times slower than any clock-pendulum 
ever constructed, instead of very much faster, as Helm- 
holtz teaches.” 
One more quotation is irresistible: “ Imagine,” says 
our author, who seems to have recovered wonderfully from 
the terrestrial cataclysm which he and the evil-doers 
