AGRICULTURAL BOTANY. 543 



12")° ('. Iioforo Cortili/.iiii,'' witli tlic .•iliovo-dcscriltod niixtiiiH', :\ tliinl was steril- 

 ized at 125° i\ iil'tor .•iddiiii,' tiic fertilizer, and a fomih was sterilized at 

 U)0° C. for 18 hovirs. 



During sterilization there was found to i>e a rorniation of more or less 

 injurious decomposition products and also a release of otherwise nonavailable 

 nitr()j?en. The decomposition products acted upon the different species of 

 plants accordinj; to their sensitiveness, and the addition of lime counteracted 

 their injurious effects. In fjeneral, sterilization seemed to relard iL?rowth for a 

 •time, hut later the jdants became more vij,'orous in the sterilized pots, often 

 exceeding in total jirowth those in the untreated pots. In every case the 

 proportion of nitrogen to total plant production was increased in the sterilized 

 pots. Except in those pots in which mustard and peas were grown in sterilized 

 meadow soil, there was an increase^ in the total plant i>roduct. which was 

 attributed to sterilization. 



Studies on the lignin and cellulose of wood, P. Spaulding {Mo. Bot. (iard. 

 Ann. h'ljt.. 11 ilHiK)). itp. 'il-58, pis. 2). — A previovis author has shown by 

 microchemical methods that cellulose occurs as a distinct lining layer in the 

 walls of wood fibers of perfectly healthy trees, and he claims that a gelatinous 

 thickening layer which reacts to the various color tests for cellulose occurs 

 very commonly in the fiber walls of the xyleni as a normal condition in a great 

 number of healthy trees, in all localities and situations. The presence of this 

 uidignified layer in the wood fibers he thinks proI)abl.v re])resents a stage of 

 arrested development and is not to be attributed to the action of fungi. Fur- 

 thermore, he claims that delignification can not be attributed to an enzym se- 

 creted by fungi. 



These statements the author has investigated to determine the prevalence of 

 cellulose in the trees of America, to test the methods of the previous author's 

 investigations, and to determine to some extent the action of fungi on wood. 

 Two sets of experiments were cai'ried on. The first, which is of a preliminary 

 nature, included but a few species of wood, while in the second about 40 of the 

 more common timber trees were tested. 



The tests for cellulose showed that it was fairly abundant in a number of 

 species but in others occurred only in very small (luantities or could not be 

 detected at all. In species of Populus and Salix it was found to form a thick 

 distinct iiuier layer of the fiber wall which seemed to. be somewhat loosely 

 attached to the sei-ondary lignified one. Cellulose was never found in the cells 

 of the oldest wood of tlu' annual rings, but was always situated in the more 

 open early wood. 



In testing the methods of the previous investigator it was found that none of 

 the woods were deli,gnified by boiling in the time stated. Apparently the woods 

 used in these experiments were more tlioroughly lignified or else their lignin 

 was held more firndy in combination. 



Tlie author thinks there is (>vidence to show the incorrectness of the claim 

 that cellulose is due to arrested development or is present in the form of reserve 

 material. In his studies he finds corroborative evidence of the delignification 

 by means of fungi. 



In conclusion, the author states that there can be no doubt that enzyms or 

 some substance exhibiting the characteristics of enzyms have been proved to 

 exist in some .of the fungi and indeed in some of the wood-rotting ones. The 

 disappearance of starch in the early stages of attack of some wood-rotting fungi 

 .seems to be generally alti'ibuted to the secretion of diastase by the fungi, and 

 lher(> api)ears to be no reason why the disappearance of lignin from the fiber 

 walls, leaving cellulose in the last stages of decay, shcmld be attributed to any 

 cause other than tiie secretion of a deliguifying enzym. 



