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NETO: F: 
[OcToBER 26, 1899 
nitrogen, oxygen, carbon, and hydrogen at ordinary temperatures 
on our earth's surface may exist in other groups of elements at 
widely different temperatures, giving rise in parts of the universe, 
even of the most divetse characters, to developments of life 
whose variety and magnificence are beyond the utmost reach of 
our imagination. 
A PAPER, entitled ‘‘ Wanted, Plant Doctors,” is to be found 
in the current issue of the Contemporary Review, in which 
the importance of the subject of plant pathology is briefly 
dealt with. While giving credit to the workers at the British 
Museum, Kew, &c., for the attention they are paying to this 
branch of science, the writer of the paper shows how far behind 
America and Germany this country is in recognising the import- 
ance of the subject. He thinks, however, that this will not be 
always so; ‘‘a time must come when every agricultural district 
will have its plant doctor, and when specialists in animal para- 
sites, cryptogamic botany, and bacteriology will be consulted in 
difficult and obscure cases, just as the help of Harley Street is 
called in by medical practitioners. The practice of plant medi- 
cine is in its infancy; but with increased competition in the 
growth of cultivated crops, the farmer cannot afford to neglect 
any help that he can get in keeping the plants under his care in 
as high a state of health as possible.” ‘‘ What better use,” 
adds the writer, ‘‘ can be found for a philanthropist’s money than 
the founding of a school of practical plant pathology, for the 
investigation of the diseases which occur in Britain ?”’ 
In the October number of the Zoo/agzst the editor, Mr. W. L. 
Distant, continues his communication on mimicry. While 
referring only to a limited number of examples, he divides his 
subject primarily into demonstrated, suggested and disputed 
cases of mimicry ; adding a section on purposeless mimicry, and 
asecond devoted to active mimicry. Under the heading of sug- 
gested mimicry the curious resemblances between certain tree- 
shrews and squirrels, as well as that between the Cape hunting- 
dog and the spotted hyzna, are rightly included ; but it seems a 
little curious to find the East African Guereza monkey, whose 
coat has been shown by Dr. J. W. Gregory to present such a 
remarkable resemblance to the pendent lichens of the trees on 
which the animal lives, included in the same category. Under 
the heading of purposeless mimicry are included cases like 
the resemblance of the bee-orchis to the insect from which it 
takes its name; while active mimicry denotes those instances 
where insects or other creatures take special measures to avail 
themselves of their resemblance to other objects. 
THE same journal likewise contains a very suggestive paper 
by Mr. C. Oldham on the mode in which bats secure their 
insect prey. It has been observed that these animals, when 
walking, carry the tail curved downwards and forwards, so that 
the membrane connecting this organ with the hind legs forms a 
kind of pouch or bag. If a large insect be encountered the 
bat seizes it with a snatch, and slightly spreading its folded 
wings and pressing them on the ground in order to steady itself, 
brings its feet forwards so as to increase the capacity of the tail- 
pouch, into which, by bending its neck and thrusting its head 
beneath the body, it pushes the insect. Although the latter, 
especially if large, will often struggle violently, when once in 
the pouch from which it is subsequently extracted and devoured 
t but rarely escapes. It is assumed that the sime method 
of capture isemployed when on the wing ; and a correspondent 
of the author, who has observed the long-eared bat picking moths 
off sallows, states that ‘‘ the bat always hovers when taking off 
the moth, and bends up the tail so as to form a receptacle for 
the insect as it drops.” 
Mr. G. C. WuHippLe and Mr. D. D. Jackson reprint, from 
the Journal of the New England Water-works Association, 
NO. 1565, VOL. 60] 
a paper on Asfertonella formosa, a diatom which sometimes 
appears in great quantities in reservoirs of drinking water, 
imparting to it a geranium-like or fishy odour, from the pro- 
duction of a substance analogous to the essential oils. Its 
development is seasonal, appearing chiefly in spring and 
autumn, Its growth is greatly favoured by strong light ; and 
the most efficacious preventative appears to be the storage of 
the water in the dark. 
THE Director of the Botanical Garden at Buitenzorg, Java, 
has issued the first number of a Avw//etZn of the Botanical 
Institute, containing a history of the Institute down to the 
present time, a plan of the buildings and of the gardens, with 
a list of the plants grown in them, and a list of the official 
publications. Besides the special laboratory for workers from 
other countries, the Institute contains laboratories for agri- 
cultural chemistry, for phyto-pathology, for agricultural zoology, 
for pharmacology, and for the study of the coffee and tobacco 
plants. 
Pror. Davip G. FAIRCHILD gives, in the Botanical 
Gazette for September, an interesting account of a visit to 
Payta, in Peru, reputed to be the driest spot on the face of the 
globe. Payta is situated about 5° S. of the equator ona coast 
which has risen 40 feet within historic times. The average 
interval between two showers is seven years; when Mr. 
Barbour Lathrop and Prof. Fairchild visited it in February, 
there had recently been rain lasting from 10 p.m. one day till 
noon the next day, the first for eight years. There are frequent 
sea-fogs. The flora consists of about nine species; of these 
seven are annuals, the seeds of which must have remained 
dormant in the ground for eight years. Notwithstanding the 
scarcity of rain, the natives subsist by the growth of the long- 
rooted Peruvian cotton, which is able to maintain itself without 
rain for seven years in the dried-up river-bed, and yields 
profitable crops of the coloured short staple cotton, which is 
used as an adulterant for wool. 
THE Calendar, for the session 1899-1900, of the University 
College of North Wales has just been issued by J. E. Cornish, 
Manchester ; and the University Correspondence College Press 
has published its London University Guide for the same period. 
THE Bulletin of Miscellaneous Information (Botanical De- 
partment) for Trinidad, No. 20, July 1899) contains a report, 
by Mr. G. Massee, on the cacao pod disease, in which he states 
that, in addition to the well-known Phytophthora omnivora, a 
second parasitic fungus, Wectrza Baznez, sp. n., occurs on the 
diseased pods. 
WE have received from the Purdue University Agricultural 
Experiment Station at Lafayette, Indiana, a parcel of reports 
(Bulletins Nos. 71-79) on various subjects o! practical importance 
to agriculturists :—The San José and other scale insects ; 
field experiments with wheat; skim milk as food for young 
growing chicken, &c. 
Pror. EtmerR GaTes describes in the Sczentific American 
a number of pictures he has obtained of the electric discharge, 
by placing a photographic plate between the two poles of a 
ten-plate electrostatic machine. The illustrations accompanying 
the article are of much the same character as those given by 
Lord Armstrong in his elaborate work on ‘‘ Electric Movement 
in Air and Water,’ but they are on a smaller scale, and 
therefore less full of detail. 
A NEW edition—the fourth—of ‘‘Our Secret Friends and 
Foes,” by Prof. Percy Frankland, F.R.S., has been published 
by the S.P.C.K. The author has re-written the chapter which 
was added to the immediately preceding edition, and has added 
some of the latest results achieved in the study of bacterial 
