The Pehrine Corpuscles in the Silkworm. 171 



and Appelsee (Eussow) ; Jamni — Les near Permeskiill (Gruner). 



O 



Berglunda near Lycksele, Lapland (J, Angstrom 1864). Belle- 

 ville, Canada (Macoun, Fowler). Near New York (Howe, Peck, 

 Austin). Fr. July. 



This rare and beautiful species may be readily known by its 

 clavate divergent branches and the large number of them in each 

 fascicle, as well as by the small stem leaves and the dense globose 

 capitulum ; in all other points its affinity hes clearly with Si^h. 

 aeutifolium. 



EXPLANATION OF PLATE LXXVII. 



Sphagnum Wulfii. 

 a. — Fertile plant. 



1. — Part of stem and branch fascicle. 

 3. — Fruit and perichsetium. 4. — Bract from same. 



5. — Stem leaves. 5 a a. — Areolation of apex of same. 5 « b. — Ditto of basal wing. 

 (!. — Leaves from middle of a divergent branch. 6/». — Point of same. 6x. — ■ 



Transverse sections, ' from upper j^art, " from lower part, ti c. — Cells ' from 



upper' part, " from lower lateral part x 200. 

 7. — Basal intermediate leaf. 

 8. — Leaf from a pendent branch. 

 9 X, — Part of section of stem. 

 10. — Part of a branch denuded of leaves. 



III. — The Pehrine Corpuscles in the Silkworm, and ivhat they 

 are analogous to. 



In the year 1865, Pasteur was instructed by the French Minister 

 of Agriculture to specially investigate and report upon the diseases 

 incident to silkworms. During the interval between the years 1853 

 and 1865, these disorders had reduced the annual production of 

 cocoons in France from sixty-five to ten millions of pounds. In 

 the admirable work which resulted from his laborious researches,* 

 the author remarks : " Certain disorders of the human race are ac- 

 companied by spots upon the skin, which originate in consequence 

 of various alterations of the intestinal canal. This is not the sole 

 observation applicable to human pathology which the experiments 

 detailed in this work will suggest to the intelligent reader." 



Diseases of the higher and lower orders of the animal kingdom 

 are undoubtedly subject to similar conditions, in their genesis, 

 resolution, or fatal issue. It is more logical as well as more con- 

 sonant with scientific method, to observe the uniformity of a patho- 

 logical law in the caries of an elephant's dentine, and the gangrene 



* ' Etude sur la Maladie des Vers-a-soie, moyen pratique assure de la com- 

 battre et d'en pre'venir le retoiu,' par M. L. Pasteur, Membre de I'liistitut Imperial 

 de France, et de la Socie'te Koyale de Londres. Paris : 1870. This work is the 

 source from which have been obtained all the facts relative to the contagious 

 disease of the silkworm, to which reference is made in this paper. 



