554 BOTANICAL GAZETTE [December 



I 



but their presence seems to have nothing to do with the transition phenomena. 

 The prevailing type of transition, present in all the smaller seedlings, is Van 

 Tieghem's type 3. Internal phloem was present in all the Solanaceae and 

 Convolvulaceae examined, with a few possible exceptions. — J. M. C. 



A disease of sugar cane. — The sugar plantations of Hawaii have suffered 

 greater loss from an endemic disease called "iliau" than from all other fungous 

 diseases combined. Lyon, now at the Experiment Station of the Hawaiian 

 Sugar Planters' Association, has investigated the disease 30 and finds that the 

 causal organism is a new species of Gnomonia (G. iliau), the imperfect stage 

 being Melanconium. The Gnomonia form is infrequent, while the Melanconium 

 form is of constant occurrence. It is a leaf-sheath disease, and its attack 

 makes it a disease of young shoots only. The entrance is effected through the 

 leaf-bases inserted on the stem below the soil surface, and thence it extends 

 upward and inward. The tightly packed roll of leaf-sheaths surrounding the 

 young stem- tip is cemented into a rigid cone, so that it is impossible for the 

 stem-tip to escape. — J. M. C. 



Diaphragms in air passages* — Le Blanc 31 has reviewed the literature on 

 the diaphragms occurring in various aquatic plants and examined other species 

 in order to discover the origin, manner of development, and function of these 

 organs. One of the most peculiar features of these plates is the occurrence of 

 perforations in the form of peculiar intercellular spaces caused by the diminu- 

 tion of the cell contents and the consequent contraction of the cells. These 

 perforations permit free gas exchange and yet do not greatly detract from the 

 rigidity of the diaphragms. The diaphragms do not seem to be due to any 

 reaction toward the aquatic medium in which the plants develop, and appear to 

 be a portion of the mechanical tissue system occasionally containing some 

 reserve food materials. — Geo. D. Fuller. 



Algae of Colorado. — Robbins 32 has published a list of the algae of Colorado, 

 which brings together all the recorded species and the additions made by the 

 author during three years of investigation. The result is a list of 143 species, 

 including 38 Cyanophyceae and 105 Chlorophyceae. Spirogyra, with 14 

 species, is the largest genus. 



The same author 33 has investigated also the occurrence of algae in certain 



30 Lyon, H. L., Iliau, an endemic cane disease. Exper. Sta. (Hawaii) Bull, 

 ii- PP- 3 2 - fi&s. 10. pi. j (colored). 1912.* 



31 Le Blanc, M., Sur les diaphragmes des canaux aeriferes des plantes. Rev. 

 Gen. Bot. 24:233-243. 1912. 



3 2 Robbins, W. W., Preliminary list of the algae of Colorado. Univ. Colorado 

 Studies 9:105-118. 191 2. 



» , Algae in some Colorado soils. Col. Agric. Exper. Sta. Bull. 184. pp. 



24-36. pis. 4. 191 2. 



