300 QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCK. 



to be the f^radual loss of vital energy. The tree, after the 

 first attack of the disease, which is often apparently the 

 most severe, throws out fresh healthy-looking leaves, and 

 exhibits for a certain period the appearance of having per- 

 fectly recovered. These fresh leaves, however, after the 

 expiration of a few months, exhibit the characteristic spot- 

 ting, and, as on the previous attack, fall prematurely. These 

 repeated attacks occurring periodically, at length seriously 

 affect the health of the tree if old and ill-cultivated, and it be- 

 comes of little or no value as a crop-producer. There is great 

 reason to believe, however, from what has been observed, that 

 high cultivation, with judicious manuring, enables the tree 

 to better sustain the attacks of the fungus, and to retain 

 strength and vigour enough to produce a fair yield of berry. 

 It is indeed ardently to be hoped that this beneficial effect 

 will be permanent. 



Whether each outburst of the disease implies a fresh in- 

 troduction of the parasite into the coffee plant, or merely 

 a periodical spore production of a permanent parasitism, 

 remains to be discovered. It is just possible to imagine 

 some subtle destructive agency operating, in addition to the 

 little red maggot which feeds on the spores, to arrest the 

 development of the fungus, but there is nothing to support 

 such a view at present. — From Dr. Thwaites' Annual Report 

 of the Peradeniya Botanic Gardens. 



4. Hetercecism. — Dr. Wolff announces that Peridermium 

 Pini, Lev., is the secidiosporous state of CoJeoaporium Com- 

 positarum, Lev., forma Senecionis {' Bot. Zeit.,' 1874', p. 184). 



5. Development of the Rye- Smut, Urocystis occulta, Rabh. — 

 Dr. Reinhold Wolff gives an elaborate paper on this subject, 

 illustrated by a plate, in the Botanische Zeitung, for Oct. 

 17-31, 1873. The species is known in Europe only as a 

 parasite on the rye (but in Australia occurs also on the 

 wheat), penetrating into the cellular tissue of the leaf, leaf- 

 sheath and culm, between the vascular bundles. (Cooke, 

 however, states that it occurs also on the leaves of Carex.) 

 The spores are generally collected in groups, with other 

 smaller spore-like bodies attached to them, but are occasion- 

 ally found simply without any of these appendages, and can 

 then only be recognised after germination. Germination 

 takes place after three or four days, the pro-mycelium filled 

 with five grained protoplasm bursting through the epispore, 

 and forming at its extremity, by a peculiar process of 

 division, from two to six " sporidia," about equal in length 

 to the pro-mycelium, which then become separated from it 

 by a septum after all the protoplasmic contents of the pro- 



