1020 Journal of Agricultural Research vol. vi, no. 25 



This case again shows that a normal heavy-laying bird may develop a 

 disease which affects the oviduct and prevents the passage of normal 

 yolks, but which does not prevent the formation of yolks in the ovary. 

 These yolks are ovulated into the body cavity. Since there was no yolk 

 in the dwarf egg, it can not be proved that the egg formation was initiated 

 by the entrance of a yolk which was later extruded. This may, however, 

 have been the case. The occurrence of a normal egg only two days later 

 shows that the ovary was in active condition. The immediate cessation 

 of normal-egg production, the continued occasional occurrence of nesting 

 records, and the condition of the ovary and oviduct at the autopsy 

 strongly suggest that the passage through the duct was already consider- 

 ably obstructed at the time the dwarf egg was produced. 



The complete record of one more case (No. 5) is available. This bird 

 did not begin to lay until November 13. She laid nearly continuously 

 and made no nesting records until July 10. During this time (240 days) 

 she produced 160 eggs. From July 10 to 23 the records show neither 

 nesting nor eggs. This probably represents a normal period of non- 

 production. No normal egg was produced by this bird after this period 

 of nonproduction. On July 23 a dwarf egg was produced. This was 

 followed by nesting records on the 24th and 27th. On the 31st another 

 dwarf egg was produced. On August 3 and 4 the bird nested and on 

 the 5th she produced a third dwarf egg. This was the last egg produced. 

 From this time until the bird was killed (Sept. 2) nesting records con- 

 tinued to occur in series similar to the clutches of normal-egg production. 

 We have no record or the contents of the dwarf egg produced on July 21. 

 The eggs produced on July 23 and August 5 contained no yolk, but had 

 as nuclei lumps of hardened albumen. The egg laid on August 5 was a 

 dwarf egg which had a stalk attached to the large end. This stalk 

 contained albumen and was covered with membrane and shell. To 

 the lumps of albumen in this egg were attached long chalaza-like fibrous 

 strings. One of these extended into the stalk. The autopsy record of 

 this bird shows the ovary in a normal period of reproduction with a series 

 of enlarging yolks, five of which were more than 1 cm. in diameter. 

 There were four empty follicles visible. The anterior half of the oviduct 

 was pathological. The walls were covered with a tumorous growth 

 which appeared to be a proliferation of the muscular tissue. The outer 

 layers of the walls of the intestine, portions of the oviduct ligament, and 

 a small portion of the surface of the ovary contained small nodules of 

 similar tissue. The body cavity contained a serous yellow liquid in 

 which were lumps of yolk. The fact that the three dwarf eggs occurred 

 between the production of the last normal egg and the complete cessation 

 of egg production suggests that the disease may have gradually obstructed 

 the passage through the duct. Whether or not the dwarf eggs were initiated 

 by yolks which entered the duct and were later extruded can not be 



