VINE AND HOP. 



67 



assigning a name to any natural production draws more attention 

 to it. 



The constant counection of Autennaria and Capnodiura, a genus 

 illustrated on a former occasion at considerable length in this 

 journal, seems exactly analogous with that of Oidium and Ery- 

 siphe. It appears however that though the transformed joints of 

 the Antenuaria never produce asci^ tlie perithecia of Capnodiuni 

 are very uncertain as to the nature of their contents. Sometimes 

 they are decidedly ascigerous and sometimes as certainly sporo- 

 ferous. Sometliing however more definite may be discovered 

 now that attention has been drawn to such points, and I should 

 be the very last to lose sight of the fact that to M. Tulasne and 

 his brother is due the credit of opening this new field to mycolo- 

 gists and lichenologists. 



Explanation of the Figures. 



Fig. 1. Erysiphe communis from 

 Hop leaves, showing the 

 origin of the sporangia 

 from the decumbent 

 threads of the mycelium. 

 From a sketch by Dr. 

 Plomley. 



Fig. 2. Pycnidia produced on the 

 moniliform threads of the 

 Oidium of the Hop leaf. 

 Dr. Plomley. 



Fig. 3. a. Pycnidia and inclosed 

 spores from the Erysiphe 

 of Convolvulus arvensis. 

 b. Pycnidia from that of Trifo- 

 lium pratense. Both from 

 sketches by Mr. Broome. 



Fig. 4. Ampelomyces quisqualis, 

 Cesati, sketched by Mr. 

 Broome. 



Fig. 5. Germination of contents of 

 utricles in the Vine mildew. 



a. One of the utricles ruptured. 



b. Granules beginning to germi- 



nate. 



c. Various stages of germination 



more highly magnified. 

 The joints marked 1,1, are 

 the two cells into which 

 tlie granule was originally 

 divided. 



d. Granules germinating within 



the utricle, 

 d'. Granules from Hop mildew. 

 A similar series of sketches 

 vras prepared by Dr. 

 Plomley from the germi- 

 nation of the contents of 

 the utricles of the Hop 

 mildew, but they have 

 been omitted with one 

 exception, as altogether 

 similar to those of the 

 Vine mildew. 



Fig. 6. Erect threads and swollen 

 articulations, the precur- 

 sors of utricles and spo- 

 rangia or pycnidia, by Dr. 

 Plomley. 



Fig. 7. Thread which has arisen 

 from germinating gra- 

 nules producing little bud- 

 like articulations. Dr. 

 Plomley. 1, 1, original 

 spore. 



Fig. 8. Sphseria Erysiphina, Berk. 

 <L- Br. 



Fig. 9 



Perithecium. 

 Ascus. 

 Sporidia. 

 Couisporium 

 Berk. A- Br 



commilitans, 



