TRANSACTIONS OF SECTION D. 407 
but of the remainder a number were always of equal descent regarding race, food 
in male and female, &c. Those have been united respectively, to form ‘ popula- 
tions,’ and such populations have been divided and distributed again in 1913 in 
different localities, and also with different gradations of food, so that last year 
more than thirty ditterent breeds on different treatments, altogether more than 
a hundred, have been raised by myself and by my assistants. 
In spite of the local dispersion or just on account of its impartiality the 
result has been very uniform. Almost all the breeds resulting from both 
Scorzonera-fed parents, even the well hatched, caused much more difficulty in 
raising with Scorzonera again, died out, or came to spin only in small percentage, 
while the Scorzonera x mulberry or mulberry XScorzonera breeds showed a strong 
advantage and combined, so to say, the ‘adaptation’ of one parent with the 
healthy state of the other (still more some of the half-Scorzonera, half-mulberry- 
fed combinations), and seem to be superior to pure mulberry descendants in 
strength, and in faculty of going through the Scorzonera treatment to spinning. 
(That may be valid, of course, only for a certain number of the offspring, which 
number follows the Mendelian law.) 
Whether really ‘crossing favours adaptation’ can be decided by this year’s 
(1914) breedings ; a further gradation prepared by corresponding copule of 1913. 
These copulz have been tried as much as possible within the same race to 
avoid confusion, but with the utmost possible variety of Scorzonera handicap- 
ping, as the grandparents besides the parents have to be considered. 
For instance, I., the 1914 breed, both parents 1913 Scorzonera-fed ; (a) all 
four grandparents 1912 Scorzonera-fed ; (6) both grandparents of one side 1912 
Scorzonera-fed, of the other side Scorzonera x mulberry (=three’ grandparents 
Scorzonera, one mulberry-fed). Further gradations to male and female: (c) 
grandparents on both sides Scorzoneraxmulberry-fed or on one side both 
grandparents Scorzonera-fed, on the other both mulberry-fed (=two grandparents 
Scorzonera, two mulberry-fed), but in different combinations; (d) grandparents 
of one side Scorzonera x mulberry, of the other both mulberry-fed (one grand- 
parent Scorzonera, three mulberry-fed) ; (e) different combinations of the half- 
Scorzonera-mulberry grandparents (i.e. fed up to the fourth moulting with 
Scorzonera, then with mulberry). 
II. Of the parents in 1913 one with mulberry (grandparents also mulberry), 
the other parent with Scorzonera (grandparents various gradations, vide I.), &c. 
The results of 1914, as far as I can check them at present, have confirmed 
those of 1912 and 1913, giving corresponding gradations of the crossed and of 
the pure breeds with regard to their adaptation to the Scorzonera treatment. 
Of some biological results, the instincts of the young worms to attack and leave 
different kinds of food, their tropisms, I shall give an account elsewhere, also 
of some special experiments of inheritance relating to the melanism, called 
the * moricund,’ to the ‘sport’ of ‘non-spinners,’ or abnormal ‘ atavistic’ wing- 
patterns. 
6. Notes on Peripatus and on Australian Land Planarians. 
By T. STEEx. 
TUESDAY, AUGUST 25. 
The following Papers were read :— 
1. Studies on Hchinoderm Larvae. By Dr. T. Morvensen. 
2. On the Worm Parasites of Tropical Queensland. By Dr. W. Nicou. 
Tt is only five years ago since the study of worm parasites was taken up 
systematically in Australia. Earlier work had been of a desultory nature. In 
tropical Australia little work was done until the foundation of the Australian 
Institute of Tropical Medicine; since then a large and representative collection 
has been made. This paper gives a brief account of that collection. 
