188 ASCOMYCETES. 



bark,i and even on young unfolding leaves. The red lemon- 

 shaped perithecia break through the bark as compact patches. 

 They are distinguished from the perithecia of N. cinnaharina 

 by their smooth exterior and their smaller asci and asco- 

 spores. 



Combative measures to be used are plentiful dressing of 

 wounded places with tar, and the burning of all infected 

 material. 



Nectria cucurbitula Fr.^ (Britain and U.S. America). This 

 parasite on conifers generally, is particularly injurious to spruce 

 (Picea). It enters the host by wounds, such as those caused 

 by the caterpillars of the spruce moth {Grapholitha pactolana), 

 or by hail. The mycelium lives chiefly in the bark and bast ; 

 during the active growth of these tissues further extension of 

 the mycelium is almost completely hindered by the formation 

 of a secondary cork, but in the resting periods of these tissues 

 of the host, new hyphae are rapidly produced. Keproduction 

 is brought about by little unicellular, and larger multicellular 

 sickle-shaped conidia produced on conidiophores. The mycelium 

 frequently proceeds as soon as formed to give off the smaller 

 variety of conidia. The dark-red perithecia are produced later 

 on the same stromata as the conidia. The asci contain eight 

 bicellular spores ; the paraphyses are very delicate and slightly 

 branched. 



The fungus sometimes occurs epidemic in spruce plantations, 

 and may be the cause of many deaths. According to Magnus, 

 the larch and cembran pine may also be attacked. As a pre- 

 ventive measure all dead parts should be cut out and burned. 



Nectria Rousseliana Tul. lives in and kills leaves of the 

 box {Buxus). 



Nectria pandani Tul.^ is said to be the cause of a disease 

 on Pandaniis, also ascribed to Melanconium pandani. The 

 Pandanus disease has been reported from the Botanic Gardens 



' Young forests in districts subject to hailstorm, (e.y, on the lower Alps 

 of Bavaria), may become completely infested with Nectria through hail-wounds. 

 (Edit.) 



^R. Hartig, UnUrsuch. aus d. forst-hotan., Inatitvt. i., 188S. 



•'Schroeter ("Ueber die Stammfaule d. Pandaneae,'' Oohn's Beitr. z. Biol, d. 

 /'Ilmize.n. Bd. i., 1895) suggests that this Melanconium is a conidial form of 

 Nectria. During the investigation of a case of a, Pandanus killed in the Palm 

 House at Edinburgh Botanic Garden, J. H. Burrage found both forms present 

 ani agreeing in order of development with Sohroeter's observations. (Edit.) 



