456 Beard. — Reproduction in Animals and Plants. 
On the Phenomena of Reproduction in 
Animals and Plants. 
The Conjugation of the Infusoria and the Meaning of the 
Processes Involved. 
BY 
J. BEARD. 
With Woodcuts 9-13. 
It has been specially interesting to study the conjugation- 
processes of this group in the light of experiences formed 
elsewhere. As is well known, the facts have not been gleaned 
without the arduous labours of many distinguished investi- 
gators. The processes appear to be difficult of observation, 
but, thanks to the brilliant work of R. Hertwig 1 and E. 
Maupas 2 * , our knowledge of them has advanced enormously 
in recent years. 
It may appear presumptuous to offer an explanation of the 
meaning of the very complicated process, but, if apology be 
called for, it may rest on the ground that it appeared necessary 
to put the theoretical ‘ law of reproduction 5 to the test in 
this case also. If it sufficed as an explanation of the facts, 
so much the better ; if it were found wanting, so much the 
worse. 
1 Hertwig, R., Ueber die Conjugation der Infusorien. Abhandl. d. bayer. Akad. 
d. Wiss., II. Cl., Bd. XVII, 1889. 
2 Maupas, E., Le rajeunissement karyogamique chez les cilies. Arch, de Zool. 
exper. 2e serie. T. vii, 1889. 
