542 
ties of the subject, the author points out that whereas 
mammals have twelve cranial nerves, in frogs and other 
ichthyopsidans the number is but ten. Consequently, the 
cuestion arises whether the two additional nerves in the 
mammal are not due to the inclusion of two segments of 
the amphibian neck in the cranium of the former. If this 
be admitted, there is a strong prima facie probability that 
the occipitai condyles of the frog are not the homological 
representatives of those of the mammal. On the other 
hand, certain phenomena in annelids lead to the conclusion 
that segments, or somites, may be intercalated in various | 
parts of the body by means of budding. If such a process 
exist in vertebrates, we could readily account for the two 
additional pairs of cranial nerves (representing as many 
segments) in the mammal as compared with the frog, with- 
out interfering with the homology of their condyles. So 
far, however, as the author is aware, no such budding 
zone is known in any vertebrate, and the hypothesis must 
consequently be regarded as merely of a tentative nature. 
To the February number of the Zoologist Mr. T. South- 
well contributes notes on Arctic whaling in 1906. The 
take of right-whales was very small, the total number 
being only seven (four from East Greenland, two from 
Davis Strait, and one from Hudson Strait), and it was only 
the high price of bone—about 25001. per ton—that rendered 
the venture profitable. The most noteworthy feature is 
the capture of the four whales in East Greenland waters, 
where none had previously been taken since 1889. The 
capture suggests that there are more whales in these waters 
than is generally believed, their accessibility or otherwise 
being largely dependent upon the condition of the ice. 
The author directs special attention to the capture of four 
Atlantic right-whales by the Harris whalers, and likewise 
to the arrival of a cargo of ‘‘ bone’ from the same species 
(regarded a few years ago as nearly extinct) at New Bedford. 
In the March number of the same journal Mr. A. H. 
Paterson, of Yarmouth, gives some interesting particulars 
of the flocks of wildfowl and other birds which visited 
Norfolk at the time of the great snowfall of last Christmas. 
No less than about sixty swans were observed at Breydon, 
the majority of which appeared to be whoopers, although 
at least one is believed to have been of the Polish ee 
and pochards were yastly more numerous than for many 
years past. q 
Part iii. of the fifth volume of Biometrika was issued 
in February. The opening article is Mr. Raymond Pearl's 
“ Biometrical Study of Conjugation in Paramecium,” con- 
cerning which some correspondence took place in our 
columns last autumn (vol. Ixxiv., Pp. 465, 584, 608). The 
memoir is of great interest. 
are differentiated from non-conjugants not only in type, as 
was well known, but also in variability and in correlation. 
Conjugant types from various sources differ less inter se 
than non-conjugants. The dimensions of the two members 
of a conjugant pair are highly correlated, and it is shown 
that this is almost certainly due to the fact that the two 
miust fit—to put the matter shortly—or else they do not 
adhere, and sooner or later separate. The significance of 
these important results is discussed with care in consider- 
able detail. Mr. J. F. Tocher contributes an account of 
an anthropometrical survey of the insane in Scotland, 
carried out at the cost of the Henderson trust under his 
direction; stature and head dimensions were measured, 
and pigmentation noted, for more than 8000 cases in the 
Scotch asylums. The memoir is illustrated by maps, and 
the whole cf the original data are reprinted, by permission 
NG; 7953, VOL. 75] 
NA TOLLE 
It is found that conjugants | 
[| APRIL 4, 1907 
of the Henderson trust, as a supplement. A short article 
by ‘‘ Student ’’ deals with a point of practical interest, viz. 
the fluctuations of sampling to be expected in counting 
with a hamacytometer, and in similar operations. For 
example, in order to obtain pure cultures of a yeast, the 
fluid is diluted until it is estimated that every two drops 
contain on the average one cell; different flasks are then 
seeded with one drop each, and it is assumed that “ the 
majority of those flasks which show growth are pure 
cultures.’’ But the question arises, what actual proportion 
may be expected to be pure? The answer is, about 76 per 
cent.; 19 per cent. will have been seeded with two cells, 
and the remainder with three or more. As no references 
are given in the article, we may point out that the series 
used as a limit to the binomial when one of the chances 
is very small, is not novel; it was deduced by Poisson 
(“ Recherches sur la Probabilité des Jugements,’’ § 81, 
p- 206), and has been discussed in detail, with illustrations, 
by Bortkewitsch (‘' Das der kleinen Zahlen,’’ 
Leipzig, 1898). 
Gesetz 
AN account of the mosses collected at Westende and 
Coxyde, in Belgium, on the dunes, sands, and reclaimed 
lands known as “‘ polders,’’ combined with a discussion 
of the physiological factors regulating their distribution, 
is contributed by Dr. J. Massart to the Bulletin du Jardin 
botanique, Brussels, vol. i., No. 6. About sixty species 
were collected, of which Syntrichia (Tortula) ruraliformis 
was the most characteristic and widely spread. 
In the report of the Government laboratories at Manila 
for the year 1905-6, the superintendent, Mr. P. C. Freer, 
reviews the general lines of research carried out in the 
biological, chemical, and serum laboratories; he also 
formulates a plan for the establishment of a marine bio- 
logical laboratory, and raises the question of founding a 
medical school in the Philippine Islands. Incidentally, Mr. 
Freer insists upon the necessity, that is not always rightly 
appreciated, for systematic botanical and entomological 
work, seeing that correct identification of plants or animals 
is an essential preliminary to the prosecution of investi- 
gation on economic products. 
In Petermann’s Mittheilungen, vol. iii., part ii., Prof. 
F. Hock presents the first part of a study of the phyto- 
geographical boundaries and regions of northern Germany. 
Beginning with the vegetation of East Prussia, the author 
states that the eastern boundary of the beech and the 
western limit of certain plants of the moors and swamps 
lie in this province, so that it may be regarded as a 
transition district between Russia and _ north-western 
Germany. The botanical region of north-western Germany 
is contrasted with the adjoining botanical provinces of 
lower Saxony, Schleswig-Holstein, and the Netherlands, 
all the latter containing various North Atlantic species that 
are absent in north-western Germany. 
Unpber the title of the ‘‘ Century Plant,’’ Prof. W. 
Trelease contributes an article on the more important 
species of Agave to the March number of the Popular 
Science Monthly, New York. The chief value of many 
of the Agaves grown in Mexico lies in the fermented 
liquors prepared from the sap. In the plains of Apam, 
south of the City of Mexico, the sap is collected from 
extensive plantations of Agave atrovirens to make 
“ pulque.’’ ** Mezcal ’’ is a liquor obtained by distilla- 
tion in another part of Mexico from Agave Tequilana and 
other species; ‘‘ sotol’’ is the product of plants of the 
liliaceous genus Dasylirion. Reference is also made to the 
varieties that furnish sisal-hemp and other fibres. 
