This vintage set of books titled "Principles of Biology" is a must-have for collectors and lovers of science and medicine. Written by Herbert Spencer and published by D. Appleton & Company in 1891, this hardcover set includes volumes 1 and 2. The books are in good condition considering their age and have been well-preserved. The language used in the books is English, making it accessible to a wider audience. The set also comes with free shipping for your convenience. Add this valuable addition to your collection today!