THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL. 



Voi,. XIV. SEPTEMBER, 1893. No. 9. 



Penicillium and Some Other Fungi. 



Bv HENRY IvESIylE OSBORN, 

 ST. PAUL, MINN. 



WITH FRONTISPIECE. 



The study of the fungi is so very easy for any one who is de- 

 sirous of applying his microscope to the discovery of facts in 

 nature that surely it will be worth while to devote some space 

 to an account of a few of them. Moreover, there are many of 

 them of the utmost practical interest to man, being intimately 

 connected with many of the most necessary of his operations 

 Tims the baker, the brewer, the dairy-man, are directly at the 

 mercy of fungi. The agriculturist is often hindered in his plans 

 by their growth, while in other cases his plans are helped. 

 The doctor has in many of his patients to contend with the 



EXPLANATION OF THE PLATE. 13. A more highly magnified view of a part of 



1. — PeiikilUum. Fig. 12, showing the greatly vacuolated 



1. The mycelium of a young colony of Penicil- character of protoplasm. 



lium, — growth from the spore of about -14. The germinating Zygospore, showing the 



three days. two conjugating hypha^ (hy-l) and (hy-2), 



2. The tip of a submerged hypha. Note the and the germinating siwre with the tliiid 

 scarcity of vacuoles. hypha (by-3}. 



3. Tip of a branching hypha. 



4. Lower portion of a submerged hypha, 3.— CV/s/ojjhs randUlns. 



showing vacuoles and the cross-walls. 15, a. The hypha (hy) surrounded by the tis- 



5. Lower portion of a submerged hypha, sue of the host showing the haustoria (h), 

 showing the lateral branching. the cell-wall of the host cell, the pioto- 



G. Bilateral branching in a submerged hypha. plasm of this cell (p. u). 



7. Lateral branch to show its relation to the 15, b. The conidia on their parent hypha. 

 parent hypha as a prolongation of it. 15, c. The conidium with its contents dividing. 



8. An aerial hypha bearing the basidia (ba), 15, d. The escaping spores of the conidial 

 sterigmata (st), and the numerous conidia generation. 



in rows. 15, e. The later stage of the process. 



9. A conidium in the act of germinating, 15, f. The motile swarm-spore of Cystopus. 

 showing the young hypha emerging. 15, g. The spores germinating on the stoma 



2.— iiridur. of a host plant 



10. The entire plant-body, showing the mycel- 15, h. The sexual reproduction by means of 

 lium below the unbranched and unicelu- the antheridia (an), and the oogonium (og). 

 lar aerial hypha? and their terminal spor- The oosphere (os) is shown and the union 

 angia (sp). between the oosphere and the antheridium 



11. More enlarged view of the mycelium show- is indicated. 



ing the protoplasm and the vacuoles. AH these figures are from nature except those 



12. A young sporangium showing the proto- of Cystopus. 

 plasm before spore formation. 



