ZONE LINES IN PLANT TISSUES

The black lines of Polyporus squamosus have been found in the wood of elms. Isolations were made from these lines and an account of the development of P. squamosus in artificial culture is given. Particular mention is made of the formation of black plates, or lines as they appear in section, in culture media and of the appearance of abnormal fructifications. Pure cultures of the fungus on sterilized wood blocks have produced black lines in the wood, similar to those occurring in nature.
From a consideration of the structure and formation of the black plates, the suggestion is made that they form the limiting layer or rind of sclerotium-like bodies buried in the attacked wood.
A review is given of sclerotium formation and structure in several species of Polyporus, and analogies are made between these sclerotia and the sclerotium-like body of P. squamosus. It is decided to distinguish the P. squamosus body from these sclerotia by naming it a pseudo-sclerotium, on the criteria previously advanced for Armillaria mellea (8).     

Breast carcinoma and malignant melanoma metastasis within a single axillary lymph node

A 58 year old lady presented with a right breast cancer and a prior history of malignant melanoma excised from the right chest wall eight years previously. An abnormal axillary lymph node resected contained features of both metastatic breast carcinoma and malignant melanoma. Following oncologic breast cancer management, the patient is well with no evidence of recurrence at three years.     

A Comparative Study of Analogue and Digital Simulation of Ion Uptake by Plants

The kinetics of the uptake of phosphate ions from dilute solutionsby rice plants was studied by use of the continuous-flow technique.A model of the uptake process was examined by simulation carriedout using analogue and digital methods. The advantages and disadvantagesof each simulation method is discussed. It appears that filmdiffusion may exert an important influence on the uptake. Theuptake efficiency [(uptake with diffusion)/(uptake with completestirring)] is calculated for various conditions.