484 BOTANICAL GAZETTE • [june 



by his latest results, which are that from papayotin both peptase and ereptase 

 may be obtained. The former is soluble in dilute NaCl and little soluble in dis- 

 tilled water, while the latter is easily soluble in pure water. That the demon- 

 stration of these two proteases in papayotin might be more complete is admitted 

 by the author. Similarly, preparations from both fresh and dry yeast show the 

 presence of peptase and ereptase. 



The proposal of Vines, after reviewing the subject, to supplant the " vegetable 

 trypsin" idea by the conclusion that the proteases of plants belong to two main 

 groups, the peptases and the ereptases, and his further classification of the former 

 into endopeptases and ectopeptases, appeal to the reviewer as unnecessary and 

 unwarranted, inasmuch as the new may prove to be as incomprehensive as was 

 the " trypsin" idea. Further, if a name must be given to something of which 

 little is known, that name should have some reference to the qualities marking 

 individuality, rather than to the mere incident of its occurrence. So far, the 

 "ectopeptase" is confined to Nepenthes. The anticipation of the author that 

 " ectopeptase " is of wide occurrence maybe justified, but in one case, namely, 

 the pitcher-liquid of Sarracenia, peptic action has not been found. 30 — Raymond 



H. Pond. 



Morphology of Pseudotsuga. — The investigation of the North American 

 representative of this interesting genus by Lawson^ 1 has filled a gap in our 

 knowledge. In general it conforms to the well-known characters of Abietineae, 

 but it presents some interesting peculiarities. The pollen grains are wingless, 

 and the mechanism for receiving them is most unusual. There is a stricture of 

 the integument above the nucellus, which results in two distinct micropylar 

 chambers. The outer chamber is partially inclosed by the infolding tip of the 

 integument, from whose inner face numerous hairlike processes are developed 

 as outgrowths from the epidermal cells. Within this chamber the pollen grains 

 are received and germinate, a tangle of tubes passing down through the inner 

 chamber to the nucellus. 



At the time of pollination (April-May in California) the pollen grain contains 

 the two disorganized prothallial cells and the generative and tube nuclei. Just 

 before tube-formation the generative cell divides to form the stalk and body cells, 

 both with distinct membranes, but soon becoming very unequal. Before the 

 tip of the nucellus is reached by the tube, the nucleus of the body cell divides 

 to form two unequal male nuclei. Fertilization takes place within 60 days 

 after pollination, and the entire nuclear contents of the tube are discharged 

 into the egg. 



The functioning megaspore is surrounded by a distinct tapetal zone, and the 

 magaspore membrane becomes conspicuous. The development of the female 



1 ■ '■ ' ■ — —■ „ 



3° Robinsow Wixifred J., A study of the digestive power of Sarracenia purpurea. 

 Torreya 8:181-194. 1908. 



3iLawson, A. A., The gametophytes and embryo of Pseudotsuga Douglasii. 

 Annals of Botany 23:163-180. pis. 12-14. r 9°9- 



