Febbuakt 7, 1908] 



SCIENCE 



211 



teeidiospores. The vinusual prevalence of 

 "cedar apples" in Nebraska is due to the 

 extensive use of the cedar as an ornamental 

 tree and for orchard wind breaks with the 

 planting of varieties of apples especially 

 susceptible to the disease. During the past 

 season, secidiospores were found in viable 

 condition during July, August, September 

 and until October 22, and it was shown that 

 spores from this period produce no evident 

 infection until the spring of the next year 

 when gTowth is resumed and the young 

 "cedar apples" become visible. 



The Bud-Eot of Carnations: F. D. Heald. 



The bud-rot of carnations is a new dis- 

 ease which has only been prevalent in Ne- 

 braska and a number of other states during 

 the past few years. The disease has been 

 proved by the writer to be due to a definite 

 species of fungus, Sporotrichum anthopJii- 

 lum Peek, which has associated with it 

 a new species of mite, Pediculoides dian- 

 thophUus Woleott, as a constant accom- 

 paniment. 



The disease affects the buds in various 

 stages of maturity and produces a rotting 

 of the petals and other flower parts, at least 

 the parts enclosed by the calyx, thus inter- 

 fering with the normal opening of the 

 flower. The disease has therefore been 

 termed the "bud-rot" of the carnation. 



A Principle of Elementary Laboratory 



Teaching for Cidture Students : Charles 



B. Shaw. 



Biological laboratory teaching in general 

 comes far short of accomplishing the results 

 expected. On the average the student de- 

 velops relatively little of that interest in 

 the subject and power of observation which 

 are the chief reasons for the existence of 

 such courses. 



A teacher is likely to find himself able to 

 stimulate a greater degree of interest and 

 effort in part of the lessons than in others. 



This fact is of primary importance. 

 Laboratory courses should be made up of 

 those lessons in which the teacher finds 

 himself able to bring the class to its maxi- 

 mum of independent effort, leaving to lec- 

 ture and demonstration the task of keeping 

 the course logically connected and rounded 

 out. 



A sort of corollary to the above seems to 

 be that courses are to be modified in the 

 direction of physiology. To reach the 

 desired end it may in some cases even be 

 necessary to omit certain standard topics of 

 morphology. In all cases the goal must be 

 kept cleai-ly in view and any needful 

 sacrifice made without limitation. 



The Influence of the Form of Carbon upon 

 the Morphology of Penicillium Cultures :, 

 Charles Thom. 



Cultures of eleven species of Penicillium 

 are presented to illustrate the wide differ- 

 ence in morphology produced by changing 

 the source of carbon in synthetic culture 

 media. For comparison the species are 

 exhibited upon potato-agar, then upon syn- 

 thetic agar in which carbon is presented: 

 (1) as granulated sugar (sucrose), (2) 

 lactose, (3) glycerine, (4) alcohol, (5) tar- 

 taric acid. Repeated cultures have shown 

 that the form of carbon presented produces 

 very marked differences in metabolism, in 

 morphology and in the changes induced by 

 cultures upon the substratum— i. e., forma- 

 tion of pigments, crystals, etc. These cul- 

 tures emphasize the importance of exact 

 definitions of substrata or culture media 

 in describing saprophytes of this genus. 



Plant Succession in Eastern Colorado: H. 



L. Shantz. 



Climatic and soil factors of the plant 

 habitat. Plant succession on areas which 

 have been broken and deserted for from 

 one to twenty-two years. Chief stages of 

 the succession. Conditions which hasten 



