362 Proceedings of Royal Society of Edinburgh. [skss. 
flight holes, indicating that some time in 1897 there had been an 
escape of a new brood of beetles, and that my experiment would 
have been successful had I had leisure to attend to it. 
In February 1898 I took out one of the branches from which 
a brood had issued, and was dissecting it with a view to making 
a museum preparation of the work of S. multistriatus , when I 
came upon some living larvse. These must, I think, have come 
from eggs laid by some of the 1897 beetles, which thus appear to 
have used for breeding purposes the very same branch in which 
they themselves had been bred. This branch — 22 inches long by 
If inches in diameter — cut in July 1896, had been paraffined at 
the cut ends to prevent excessive loss of mixture, but by 1897 
must have lost its freshness and been dry and dead. 
In order to allow the larvse present in the half-dissected speci- 
men of elm to attain their full development, the branch was placed 
in a cotton sack, and exposed in the Garden to all weathers. On 
15th July 1898 beetles began to issue, and from this dead dry 
branch I obtained on 
1898, July 15 ... 4 multistriatus. 
n 
a 
33 
33 
18 ... 2 
23 ... 3 
24 ... 3 
27 ... 2 
29 ... 1 
33 
33 
33 
33 
33 
With this fresh supply of multistriatus I started a new experi- 
ment. 
Method of Experiment. 
Two branches of Ulmus campestris , freshly cut in the Royal 
Botanic Garden, each measuring 2 feet long by 2f inches in dia- 
meter, were placed in a cotton sack, after being paraffined, i.e ., the 
cut ends of the branches had been dipped in melted paraffin, which 
when solidified had formed a crust over the cut surfaces. This 
coating of paraffin, by causing retention of moisture, kept the 
branches fresh for a much longer time than they would have 
remained so without the treatment. To the sack containing the 
elm branches eleven S. multistriatus were added between July 15 
and July 19, 1898. The eleven were placed in without their sex 
being determined, as determination of these small beetles, with a 
