August Weismann 
Germ-Plasm [PDF ebook] 
A Theory of Heredity

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Mr. Hartland’s book will win the sympathy of all earnest students, both by the knowledge it displays, and by a thorough love and appreciation of his subject, which is evident throughout. – Spectator.