Eumycetes. 263 



lected at Cold Spring Harbor, Long Island, where the ascocarps 

 of Lachnea were found in large numbers upon decaying wood in 

 damp places. The ascocarps appear to be frequently produced in 

 crops, as a considerable number of about the samc age are often 

 found on a Single log. If all of these are removed while still young, 

 a second crop will usually appear in a few days. If now the young 

 ascocarps are removed as they appear, successive crops may continue 

 to be produced for some time. By this means a large number of 

 young stages can be quite easily obtained. 



The results of the investigations are summarized as follows: 



The mature ascocarp of Lachnea is disc-shaped. The hymenium 

 forms the upper surface, while the rim and lower surface are covered 

 by a thick-walled cortical layer. The center is composed of rather 

 loosely interlacing hyphae. 



The ascogonium is the penultimate cell of a row of about nine. 



The ascogonium is early surrounded by vegetative hyphae, the 

 outer of which form the first part of the cortex, while those around 

 the ascogonium remain active and give rise on one side to more of 

 the cortex and on the other to hyphae which still produce para- 

 physes. When a part of the cortex is once formed, the development 

 of the hyphae composing that part ceases. The cells between the 

 cortex and hymenium, however, remain active and add to the cortex 

 and to the hyphae which produce paraphyses. 



The ascogenous hyphae are large and branch profusely. At the 

 ends of these are formed typical hooks, consisting of binucleate 

 penultimate and uninucleate ultimate and antepenultimate cells, The 

 two nuclei of a penultimate cell may fuse to form the nucleus of 

 an ascus, or they may divide and give rise to the four nuclei of 

 another hook. The uninucleate ultimate cell usually grows down 

 and fuses with the antepenultimate cell, after which the two nuclei 

 may give rise to the nuclei of another hook, or they may fuse to 

 form an ascus. 



When the hymenium is first formed, it is covered by theyounger 

 setae of the cortex, but as its diameter is increased and its level 

 raised by the multiplication of the number of asci and paraphyses, 

 it comes to be exposed. 



No fusion of nuclei was observed in either the ascogonium or 

 ascogenous h5^phae, except where two nuclei fuse to form the pri- 

 mary nucleus of an ascus. 



The nuclei of the ascogonium and ascogenous h37^phae appear 

 to be entirely similar except for size, and the same number of 

 chromosomes, five, persists throughout their divisions. When the 

 chromosomes are first formed, they are frequently grouped in a 

 mass resembling a second nucleolus. The chromosomes become 

 connected with a centrosome which was not apparent during the 

 resting stage. This centrosome divides, and the two daughter cen- 

 trosomes come to be situated at the poles of the spindle. At meta- 

 phase the five chromosomes divide, and at anaphase five pass to 

 each pole. The daughter nuclei are usually organized at some 

 distance from each other, but sometimes the}^ are so close together 

 that they resemble fusing nuclei. 



The first division in the ascus is heterotypic. Synizesis is pro- 

 duced by the contraction of a Single spireme. After s^mizesis the 

 spireme splits longitudinally. The two halves come together again, 

 after which the spireme contracts considerably and Segments into 

 five elongated chromosomes. A centrosome makes its appearance 



