ERA IND T. 
30 PROF. JULIUS MACLEOD ON TEN 
TABLE XIV. 
| Mnium hornum, Linn.—One stem with 43 leaves. 
| : Characters, Particulars of the leaves in the 10th interval. 
A. 3 
E. Breadth, leaves .......... s... 181 124 188 087 115 - 
E # base leaves ,.:....... 071 0:75 076 0:66 0:75 
| ‘ Marginal-teeth .......... 1:1... 58 52 58 46 60 
[ AW (D9 4 SE TRECE RET ER Sess yd 9 9 6 T 
Table XXVI. (breadth), minimum : by means of the lowest figure of æ in 
Table XIV. (0°87) we exclude spinosum, undulatum, rostratum, affine, punc- 
tatum, and subglobosum. Using the maximum table, we exclude orthorrhyn- 
chum by means of the highest figure of æ (1:38). 
Table XX XII. (marginal teeth), minimum: by means of the lowest value 
of æ (46) we exclude undulatum, previously excluded. The maximum table 
enables us to exclude by means of the highest value of æ (60) : punctatum, 
subglobosum, and orthorrhynchum (previously excluded), and also serratum. 
The stem æ thus belongs to hornum or cuspidatum. 
Table XXXIV. (teeth on the nerve): cuspidatum is excluded by the 
maximum table. The stem w thus belongs to the species Mnium hornum. 
$20. REMARKS ON THE USE OF NUMBERS FOR THE IDENTIFICATION OF 
SPECIMENS.—For the identification of specimens we have three methods at 
our disposal, each of them allowing verification of the result given by the 
others. 
Each of the three methods affords a rather wide range of possibilities. 
Applying the first method (with one leaf of one stem, see $ 17) we may 
very often use the limit-tables in two ways, starting from the first or from 
the last table: this allows verification (see the example in $ 17). Moreover, 
it is possible to measure a greater number of properties, for instance (taking 
the Acrocarpic Mosses as an example) : the length of the so-called fruit-stalk, 
some properties of the teeth of the peristome, the dimensions of the ripe 
spores. A section of a fertile stem (exactly in the transverse direction) 
at the insertion of the longest leaf would furnish some more measurable 
properties. Of course, the practical value of the method will increase in 
proportion as the number of the measured properties becomes greater *, 
Using the SECOND METHOD (see $ 19) we may take more than two speci- 
mens and, in case of need, verify the result as many times as 
the material at our disposal. 
is afforded by 
* I have measured 38 characters of Carabus. Tn this paper I limit myself to 14 characters 
of Mnium, because I want to avoid too long a delay in the publication of a first paper on the 
results of the work with which I have been occupied for many years. 
CARNE E SERT e Wet rw qp TA METER E TS MS EINE LE 
ETER 
